CMP Journal 2025-05-28
Statistics
Nature: 25
Nature Materials: 1
Nature Nanotechnology: 1
Physical Review Letters: 9
Physical Review X: 3
Review of Modern Physics: 1
arXiv: 65
Nature
Electricity-driven enzymatic dynamic kinetic oxidation
Original Paper | Biocatalysis | 2025-05-27 20:00 EDT
Beibei Zhao, Yuanyuan Xu, Qin Zhu, Aokun Liu, Xichao Peng, Tianying Zhang, Lu Yu, Yan Zhang, Xiaoqiang Huang
Electrochemistry is undergoing a resurgence in synthetic chemistry and boasts compelling advantages1. Repurposing natural enzymes through synthetic chemical strategies holds significant promise for exploring new chemical space2-6. Elegant strategies, including directed evolution7-10, artificial enzymes11, and photoenzymatic catalysis12,13 have demonstrated their capacities for expanding the applications of enzymes in both academia and industry. However, the integration of electrochemistry with enzymes has primarily been limited to replicating previously established enzyme functions14-16. Key challenges in achieving new enzyme reactivity with electricity include compatibility issues and difficulties in heterogeneous electron transfer. Here we report the reshaping of thiamine-dependent enzymes with ferrocene-mediated electrocatalysis to unlock an unnatural dynamic kinetic oxidation of α-branched aldehydes. This robust electroenzymatic approach yields various bioactive (S)-profens with up to 99% enantiomeric excess, is applicable with whole cells overexpressing the enzyme and using down to 0.05 mol% enzyme loadings. Mechanistic investigations reveal multiple functions of the electroenzyme in the precise substrate discrimination, accelerating racemization, and facilitating kinetically matched electron transfer events.
Biocatalysis, Enzymes
Protein-primed homopolymer synthesis by an antiviral reverse transcriptase
Original Paper | Bacteriophages | 2025-05-27 20:00 EDT
Stephen Tang, Rimantė Žedaveinytė, Nathaniel Burman, Shishir Pandey, Josephine L. Ramirez, Louie M. Kulber, Tanner Wiegand, Royce A. Wilkinson, Yanzhe Ma, Dennis J. Zhang, George D. Lampe, Mirela Berisa, Marko Jovanovic, Blake Wiedenheft, Samuel H. Sternberg
Bacteria defend themselves from viral predation using diverse immune systems, many of which target foreign DNA for degradation1. Defense-associated reverse transcriptase (DRT) systems provide an intriguing counterpoint to this strategy by leveraging DNA synthesis instead2,3. We and others recently showed that DRT2 systems use an RNA template to assemble a de novo gene that encodes an antiviral effector protein, Neo4,5. It remains unknown whether similar mechanisms of defense are employed by other related DRT families. Focusing on DRT9, here we uncover an unprecedented mechanism of DNA homopolymer synthesis. Viral infection triggers polydeoxyadenylate (poly-dA) accumulation in the cell, driving abortive infection and population-level immunity. Cryo-EM structures reveal how a noncoding RNA serves as both a structural scaffold and reverse transcription template to direct hexameric complex assembly and poly-dA synthesis. Remarkably, biochemical and functional experiments identify tyrosine residues within the reverse transcriptase itself that likely prime DNA synthesis, leading to the formation of high-molecular weight protein-DNA covalent adducts. Synthesis of poly-dA by DRT9 in vivo is regulated by the competing activities of phage-encoded triggers and host-encoded silencers. Collectively, our work unveils a novel nucleic acid-driven defense system that expands the paradigm of bacterial immunity and broadens the known functions of reverse transcriptases.
Bacteriophages, Cryoelectron microscopy, DNA, Non-coding RNAs
Pt migration-lockup in zeolite for stable propane dehydrogenation catalyst
Original Paper | Chemical engineering | 2025-05-27 20:00 EDT
Zhikang Xu, Mingbin Gao, Yao Wei, Yuanyuan Yue, Zhengshuai Bai, Pei Yuan, Paolo Fornasiero, Jean-Marie Basset, Bingbao Mei, Zhongmin Liu, Haibo Zhu, Mao Ye, Xiaojun Bao
The shale gas revolution has shifted propylene production from naphtha cracking to on-purpose production with propane dehydrogenation (PDH) as the dominant technology1-9. Because PDH is endothermic and requires high temperatures that favour sintering and coking, the challenge is to develop active and stable catalysts1-3 that are sufficiently stable10,11. Zeolite-supported Pt-Sn catalysts have been developed to balance activity, selectivity and stability12,13, and more recent work documented a PDH catalyst based on zeolite-anchored single rhodium atoms with exceptional performance and stability14. Here we show for silicalite-1 (S-1) that migration of encapsulated Pt-Sn2 clusters and hence agglomeration and anchoring within the zeolite versus agglomeration on the external surface can be controlled by adjusting the length of the S-1 crystals’ b-axis. We find that when this axis is longer than 2.00 μm, migration of Pt-Sn2 monomers during PDH results in intra-crystalline formation of (Pt-Sn2)2 dimers that are securely locked in the channels of S-1 and capable of converting pure propane feed to propylene at 550 °C for more than 6 months with 98.3% selectivity at 91% equilibrium conversion. This performance exceeds that of other Pt-based PDH catalysts and approaches that of the Rh-based catalyst. While synthesis requirements and cost are currently prohibitive for industrial use, we anticipate that our approach to controlling the migration and lockup of metals in zeolites may enable to development of other noble metal catalysts that offer extended service lifetimes in industrial applications15-17.
Chemical engineering, Heterogeneous catalysis
Cross-tissue multicellular coordination and its rewiring in cancer
Original Paper | Cancer microenvironment | 2025-05-27 20:00 EDT
Qiang Shi, Yihan Chen, Yang Li, Shishang Qin, Yu Yang, Yang Gao, Linnan Zhu, Dongfang Wang, Zemin Zhang
The multicellular coordination that underlies tissue homeostasis and disease progression is of fundamental interest1,2,3,4,5. However, how diverse cell types are organized within tissue niches for cohesive functioning remains largely unknown. Here we systematically characterized cross-tissue coordinated cellular modules in healthy tissues, uncovering their spatiotemporal dynamics and phenotypic associations, and examined their rewiring in cancer. We first compiled a comprehensive single-cell transcriptomic atlas from 35 human tissues, revealing substantial inter-tissue variability in cellular composition. By leveraging covariance in cellular abundance, we identified 12 cellular modules with distinct cellular compositions, tissue prevalences and spatial organizations, and demonstrated coordinated intercellular communication within cellular modules using in situ spatial and in vivo perturbation data. Among them, two immune cellular modules in the spleen showed contrasting chronological dynamics with ageing. Analysis of multicellular changes in the breast revealed a menopausal trajectory associated with fibroblast dynamics. Furthermore, interrogation across cancer types uncovered simultaneous rewiring of two types of multicellular ecosystem during tumour progression, including the loss of tissue-specific healthy organization and the emergence of a convergent cancerous ecosystem. These findings reveal fundamental organizing principles of multicellular ecosystems in health and cancer, laying a foundation for further investigations into tissue-level functional coordination across diverse contexts.
Cancer microenvironment, Computational biology and bioinformatics, Multicellular systems
CoQ imbalance drives reverse electron transport to disrupt liver metabolism
Original Paper | Bioenergetics | 2025-05-27 20:00 EDT
Renata L. S. Goncalves, Zeqiu Branden Wang, Jillian K. Riveros, Güneş Parlakgül, Karen E. Inouye, Grace Yankun Lee, Xiaorong Fu, Jani Saksi, Clement Rosique, Sheng Tony Hui, Mar Coll, Ana Paula Arruda, Shawn C. Burgess, Isabel Graupera, Gökhan S. Hotamışlıgil
Mitochondrial reactive oxygen species (mROS) are central to physiology1,2. Excess mROS production has been associated with several disease states2,3; however, the precise sources, regulation and mechanism of generation in vivo remain unclear, which limits translational efforts. Here we show that in obesity, hepatic coenzyme Q (CoQ) synthesis is impaired, which increases the CoQH2 to CoQ (CoQH2/CoQ) ratio and drives excessive mROS production through reverse electron transport (RET) from site IQ in complex I. Using multiple complementary genetic and pharmacological models in vivo, we demonstrate that RET is crucial for metabolic health. In patients with steatosis, the hepatic CoQ biosynthetic program is also suppressed, and the CoQH2/CoQ ratio positively correlates with disease severity. Our data identify a highly selective mechanism for pathological mROS production in obesity, which can be targeted to protect metabolic homeostasis.
Bioenergetics, Enzyme mechanisms, Metabolic disorders
Detection of X-ray emission from a bright long-period radio transient
Original Paper | Compact astrophysical objects | 2025-05-27 20:00 EDT
Ziteng Wang, Nanda Rea, Tong Bao, David L. Kaplan, Emil Lenc, Zorawar Wadiasingh, Jeremy Hare, Andrew Zic, Akash Anumarlapudi, Apurba Bera, Paz Beniamini, A. J. Cooper, Tracy E. Clarke, Adam T. Deller, J. R. Dawson, Marcin Glowacki, Natasha Hurley-Walker, S. J. McSweeney, Emil J. Polisensky, Wendy M. Peters, George Younes, Keith W. Bannister, Manisha Caleb, Kristen C. Dage, Clancy W. James, Mansi M. Kasliwal, Viraj Karambelkar, Marcus E. Lower, Kaya Mori, Stella Koch Ocker, Miguel Pérez-Torres, Hao Qiu, Kovi Rose, Ryan M. Shannon, Rhianna Taub, Fayin Wang, Yuanming Wang, Zhenyin Zhao, N. D. Ramesh Bhat, Dougal Dobie, Laura N. Driessen, Tara Murphy, Akhil Jaini, Xinping Deng, Joscha N. Jahns-Schindler, Y. W. Joshua Lee, Joshua Pritchard, John Tuthill, Nithyanandan Thyagarajan
Recently, a class of long-period radio transients (LPTs) has been discovered, exhibiting emission thousands of times longer than radio pulsars1,2,3,4,5. These findings, enabled by advances in wide-field radio surveys, challenge existing models of rotationally powered pulsars. Proposed models include highly magnetized neutron stars6, white-dwarf pulsars7 and white-dwarf binary systems with low-mass companions8. Although some models predict X-ray emission6,9, no LPTs have been detected in X-rays despite extensive searches1,2,3,4,5,10. Here we report the discovery of an extremely bright LPT (10-20 Jy in radio), ASKAP J1832-0911, which has coincident radio and X-ray emission, both with a 44.2-minute period. Its correlated and highly variable X-ray and radio luminosities, combined with other observational properties, are unlike any known Galactic object. The source could be an old magnetar or an ultra-magnetized white dwarf; however, both interpretations present theoretical challenges. This X-ray detection from an LPT reveals that these objects are more energetic than previously thought and establishes a class of hour-scale periodic X-ray transients with a luminosity of about 1033 erg s-1 linked to exceptionally bright coherent radio emission.
Compact astrophysical objects, Time-domain astronomy, Transient astrophysical phenomena
Two distinct host-specialized fungal species cause white-nose disease in bats
Original Paper | Fungal genomics | 2025-05-27 20:00 EDT
Nicola M. Fischer, Imogen Dumville, Benoit Nabholz, Violeta Zhelyazkova, Ruth-Marie Stecker, Anna S. Blomberg, Serena E. Dool, Marcus Fritze, Marie-Ka Tilak, Andriy-Taras Bashta, Clothilde Chenal, Anna-Sophie Fiston-Lavier, Sebastien J. Puechmaille
The emergence of infectious diseases, particularly those caused by fungal pathogens, poses serious threats to public health, wildlife and ecosystem stability1. Host-fungus interactions and environmental factors have been extensively examined2,3,4. However, the role of genetic variability in pathogens is often less well-studied, even for diseases such as white-nose in bats, which has caused one of the highest disease-driven death tolls documented in nonhuman mammals5. Previous research on white-nose disease has primarily focused on variations in disease outcomes attributed to host traits or environmental conditions6,7,8, but has neglected pathogen variability. Here we leverage an extensive reference collection of 5,479 fungal isolates from 27 countries to reveal that the widespread causative agent is not a single species but two sympatric cryptic species, each exhibiting host specialization. Our findings provide evidence of recombination in each species, but significant genetic differentiation across their genomes, including differences in genome organization. Both species contain geographically differentiated populations, which enabled us to identify the species introduced to North America and trace its source population to a region in Ukraine. In light of our discovery of the existence of two cryptic species of the causative agent of white-nose disease, our research underscores the need to integrate the study of pathogen variability into comprehensive disease surveillance, management and prevention strategies. This holistic approach is crucial for enhancing our understanding of diseases and implementing effective measures to prevent their spread.
Fungal genomics, Microbial ecology, Pathogens, Population genetics
Astrocyte morphogenesis requires self-recognition
Original Paper | Glial development | 2025-05-27 20:00 EDT
John H. Lee, Alina P. Sergeeva, Göran Ahlsén, Seetha Mannepalli, Fabiana Bahna, Kerry M. Goodman, Runzhe Xu, Baljit S. Khakh, Joshua A. Weiner, Lawrence Shapiro, Barry Honig, S. Lawrence Zipursky
Self-recognition is a fundamental cellular process across evolution and forms the basis of neuronal self-avoidance1,2,3,4. Clustered protocadherin (cPcdh) proteins, which comprise a large family of isoform-specific homophilic recognition molecules, have a pivotal role in the neuronal self-avoidance that is required for mammalian brain development5,6,7. The probabilistic expression of different cPcdh isoforms confers unique identities on neurons and forms the basis for neuronal processes to discriminate between self and non-self5,6,8. Whether this self-recognition mechanism also exists in astrocytes remains unknown. Here we report that γC3, a specific isoform in the Pcdhγ family, is enriched in human and mouse astrocytes. Using genetic manipulation, we demonstrate that γC3 acts autonomously to regulate astrocyte morphogenesis in the mouse visual cortex. To determine whether γC3 proteins act by promoting recognition between processes of the same astrocyte, we generated pairs of γC3 chimeric proteins that are capable of heterophilic binding to each other, but incapable of homophilic binding. Co-expression of complementary heterophilic binding isoform pairs in the same γC3-null astrocyte restored normal morphology. By contrast, chimeric γC3 proteins individually expressed in single γC3-null mutant astrocytes did not. These data establish that self-recognition mediated by γC3 contributes to astrocyte development in the mammalian brain.
Glial development, Morphogenesis, Neural patterning
Preoptic EP3R neurons constitute a two-way switch for fever and torpor
Original Paper | Neurophysiology | 2025-05-27 20:00 EDT
Natalia L. S. Machado, Nicole Lynch, Luis H. A. Costa, David Melville, Hakan Kucukdereli, Satvinder Kaur, Alexander S. Banks, Francesca Raffin, Oscar D. Ramirez-Plascencia, Sydney Aten, Janayna D. Lima, Sathyajit S. Bandaru, Richard D. Palmiter, Clifford B. Saper
Many species use a temporary decrease in body temperature and metabolic rate (torpor) as a strategy to survive food scarcity in a cool environment. Torpor is caused by preoptic neurons that express a variety of peptides and receptors1,2,3,4,5,6,7, but no single genetic marker has been found for this population. Here we report that expression of the prostaglandin EP3 receptor (EP3R) marks a unique population of median preoptic nucleus (MnPO) neurons that are required for both torpor and lipopolysaccharide-induced fever8. The MnPO-EP3R neurons produce persistent fever responses when inhibited and prolonged hypothermic responses when activated either chemogenetically or optogenetically, even for brief periods of time. The mechanism for these prolonged responses appears to involve increases in intracellular levels of cAMP and calcium that may persist for many minutes up to hours beyond the termination of a stimulus. These properties endow the population of MnPO-EP3R neurons with the ability to act as a two-way switch for the hypothermic and hyperthermic responses that are required for survival.
Neurophysiology, Neuroscience
Radiative forcing reduced by early twenty-first century increase in land albedo
Original Paper | Climate change | 2025-05-27 20:00 EDT
Zhengyang Hou, Liqiang Zhang, Jingjing Peng, Giovanni Forzieri, Aolin Jia, Zhiqiang Xiao, Ying Qu, Jintai Lin, Duoying Ji, Zidong Zhu, Xin Yao, Shuwen Peng, Lanpu Zhao, Wenjie Fan, Zhaocong Wu, Hao Geng, Qihao Wang, Chenghu Zhou, Suhong Liu, Liangpei Zhang
Surface albedo greatly affects how much energy the Earth absorbs. Intensive human activities and accelerated climate change have altered surface albedo across spatial and temporal scales1,2,3, yet assessments of the effects of land use or land cover (LULC) and snow variations on land surface albedo are scarce at the global scale. As a result, the global land surface albedo dynamics over recent decades and their corresponding radiative forcing to the climate system remain poorly understood4,5,6,7,8,9. Here we quantify the individual and combined effects of snow cover dynamics, LULC conversions and non-conversion regions on albedo variations during 2001-2020 and estimate their induced radiative forcing. We show that the negative radiative forcing induced by the global land surface albedo change was -0.142 (-0.158, -0.114) W m-2 over the past two decades. The global snow-free land surface albedo increased by 2.2% (P < 0.001), with a negative radiative forcing of -0.164 (-0.186, -0.138) W m-2 (P < 0.001). The magnitude of this negative forcing is sevenfold larger than the positive forcing induced by snow dynamics, and equivalent to 59.9% of that caused by CO2 emissions from 2011 to 201910. The global radiative forcing due to albedo changes in LULC non-conversion regions is 3.9 to 8.1 times greater than that from LULC conversions. The radiative forcing induced by albedo changes highlights the important role of land surface dynamics in modulating global warming.
Climate change, Climate-change ecology, Cryospheric science, Environmental impact
The shaping of terrestrial planets by late accretions
Review Paper | Asteroids, comets and Kuiper belt | 2025-05-27 20:00 EDT
Simone Marchi, Jun Korenaga
Terrestrial planets–Mercury, Venus, Earth and Mars–formed by the accretion of smaller objects. The Earth was probably the latest terrestrial planet to form and reached about 99% of its final mass within about 60-100 Myr after condensation of the first solids in the Solar System. This Review examines the disproportionate role of the last approximately 1% of planetary growth, or late accretion, in controlling the long-term evolution of the Earth and other terrestrial planets. Late accretion may have been responsible for shaping Earth’s distinctive geophysical and chemical properties and generating pathways conducive to prebiotic chemistry. Differences in the late accretion of a planet may provide a rationale for interpreting the distinct properties of Venus and Earth (for example, tectonism, atmospheric composition, water content), the surface dichotomy of Mars and the high core-to-silicate mass ratio of Mercury. Large collisions and ensuing processes are likely to occur and modulate the evolution of rocky exoplanets as well, and they should be considered in our quest to find Earth-like worlds.
Asteroids, comets and Kuiper belt, Atmospheric dynamics, Early solar system, Geodynamics, Inner planets
Air pollution modulates trends and variability of the global methane budget
Original Paper | Atmospheric chemistry | 2025-05-27 20:00 EDT
Yuanhong Zhao, Bo Zheng, Marielle Saunois, Philippe Ciais, Michaela I. Hegglin, Shengmin Lu, Yifan Li, Philippe Bousquet
Air pollution affects climate through various complex interactions1. It perturbs the Earth’s radiative energy balance and alters the atmospheric oxidation capacity, which determines the lifetimes of short-lived climate forcers, such as methane1. A key mechanism in this dynamic is the impact of air pollutants on the hydroxyl radical (OH), the most important oxidant in the troposphere, which accounts for approximately 90% of the methane chemical sink2. However, a comprehensive quantification of the interactions between air pollutants, OH and methane over decadal timescales remains incomplete2. Here we develop an integrated observation-driven and model-driven approach to quantify how variations in key air pollutants influence the methane chemical sink and alter the methane budget. Our results indicate that, from 2005 to 2021, enhanced tropospheric ozone, increased water vapour and decreased carbon monoxide levels collectively contributed to a 1.3-2.0 Tg year-1 increase per year in the global methane sink, thereby buffering atmospheric methane growth rates. This increase in the methane sink was primarily concentrated in tropical regions and exhibited a north-south asymmetry. Periods of high methane growth were typically linked to abrupt OH level declines driven by fluctuations in air pollutants, especially during extreme events such as mega wildfires and the COVID-19 pandemic. Our study suggests a trade-off between O3 pollution control and methane removal mediated by OH and highlights the risk of increasing carbon monoxide emissions from widespread wildfires.
Atmospheric chemistry, Climate sciences, Environmental sciences
In vivo haemopoietic stem cell gene therapy enabled by postnatal trafficking
Original Paper | Gene therapy | 2025-05-27 20:00 EDT
Michela Milani, Anna Fabiano, Marta Perez-Rodriguez, Raisa Jofra Hernandez, Alessandra Zecchillo, Erika Zonari, Sofia Ottonello, Luca Basso-Ricci, Cesare Canepari, Monica Volpin, Valeria Iannello, Valentina Capo, Pamela Quaranta, Luca Seffin, Fabio Russo, Mauro Biffi, Leonardo Ormoli, Chiara Brombin, Filippo Carlucci, Antonella Forlino, Marta Filibian, Eugenio Montini, Serena Scala, Anna Villa, Juan Antonio Bueren, Paula Rio, Alessandro Aiuti, Alessio Cantore, Luigi Naldini
Lentiviral vector (LV)-mediated ex vivo gene therapy for haematopoietic stem and progenitor cells (HSPCs) has delivered on the promise of a ‘one-and-done’ treatment for several genetic diseases1. However, ex vivo manipulation and patient conditioning before transplantation are major hurdles that could be overcome by an in vivo approach. Here we demonstrate that in vivo gene delivery to HSPCs after systemic LV administration is enabled by the substantial trafficking of these cells from the liver to the bone marrow in newborn mice. We improved gene-transfer efficiency using a phagocytosis-shielded LV, successfully reaching bona fide HSPCs capable of long-term multilineage output and engraftment after serial transplantation, as confirmed by clonal tracking. HSPC mobilization further increased gene transfer, extending the window of intervention, although permissiveness to LV transduction declined with age. We successfully tested this in vivo strategy in mouse models of adenosine deaminase deficiency, autosomal recessive osteopetrosis and Fanconi anaemia. Interestingly, in vivo gene transfer provided a selective advantage to corrected HSPCs in Fanconi anaemia, leading to near-complete haematopoietic reconstitution and prevention of bone marrow failure. Given that circulating HSPCs in humans are also most abundant shortly after birth, in vivo HSPC gene transfer holds strong translational potential across multiple diseases.
Gene therapy, Stem-cell research
Dating the evolution of oxygenic photosynthesis using La-Ce geochronology
Original Paper | Element cycles | 2025-05-27 20:00 EDT
Laureline A. Patry, Pierre Bonnand, Maud Boyet, Munira Afroz, Dylan T. Wilmeth, Brittany Ramsay, Philippe Nonnotte, Martin Homann, Pierre Sansjofre, Philip W. Fralick, Stefan V. Lalonde
There is ongoing debate as to when oxygenic photosynthesis evolved on Earth1,2. Geochemical data from ancient sediments indicate localized or ephemeral photosynthetic O2 production before the Great Oxidation Event (GOE) approximately 2.5-2.3 billion years ago (Ga), and currently suggest Archaean origins, approximately 3 Ga or earlier3,4,5,6,7,8,9. However, sedimentary records of the early Earth often suffer from preservation issues, and poor control on the timing of oxidation leaves geochemical proxy data for the ancient presence of O2 open to critique10,11,12,<a aria-label=”Reference 13” data-test=”citation-ref” data-track=”click” data-track-action=”reference anchor” data-track-label=”link” href=”https://www.nature.com/articles/s41586-025-09009-8#ref-CR13“ id=”ref-link-section-d24449928e555” title=”Slotznick, S. P. et al. Reexamination of 2.5-Ga “whiff” of oxygen interval points to anoxic ocean before GOE. Sci. Adv. 8, eabj7190 (2022).”>13. Here, we report rare Earth element data from three different Archaean carbonate platforms preserved in greenstone belts of the northwest Superior Craton (Canada), which were deposited by the activity of marine photosynthetic bacteria 2.87 Ga, 2.85 Ga and 2.78 Ga. All three indicate O2 production before the GOE in the form of significant depletions in cerium (Ce), reflecting oxidative Ce removal from ancient seawater, as occurs today14. Using 138La-138Ce geochronology, we show that La/Ce fractionation, and thus Ce oxidation, occurred at the time of deposition, making these the oldest directly dated Ce anomalies. These results place the origin of oxygenic photosynthesis in the Mesoarchaean or earlier and bring an important new perspective on a long-standing debate regarding Earth’s biological and geochemical evolution.
Element cycles, Geochemistry, Marine chemistry, Palaeontology
Light-triggered regionally controlled n-doping of organic semiconductors
Original Paper | Conjugated polymers | 2025-05-27 20:00 EDT
Xin-Yi Wang, Yi-Fan Ding, Xiao-Yan Zhang, Yang-Yang Zhou, Chen-Kai Pan, Yuan-He Li, Nai-Fu Liu, Ze-Fan Yao, Yong-Shi Chen, Zhi-Hao Xie, Yi-Fan Huang, Yu-Chun Xu, Hao-Tian Wu, Chun-Xi Huang, Miao Xiong, Li Ding, Zi-Di Yu, Qi-Yi Li, Yu-Qing Zheng, Jie-Yu Wang, Jian Pei
Doping is a primary method to modulate the electrical properties of semiconductors, enabling the fabrication of various homojunctions/heterojunctions and complex devices1,2,3,4,5,6,7,8. For organic semiconductors (OSCs), the electrical performance has been extensively improved by developing doping methods and dopants9,10,11,12,13. However, compared with the state-of-the-art spatial resolution of inorganic semiconductor fabrication processes, OSCs lag far behind, limiting the construction of complex organic electronic devices5. Here we present a facile light-triggered doping strategy and develop a series of inactive photoactivable dopants (iPADs) for regionally controlled n-doping of OSCs. By converting iPADs into active dopants through ultraviolet (UV) exposure, controllable doping of various n-type OSCs with high electrical conductivity greater than 30 S cm-1 has been realized. Using iPADs can substantially improve the performances of OSCs in transistors, logic circuits and thermoelectrics. Also, regionally controlled doping is demonstrated in OSCs with a record resolution down to 1 μm. Overall, our strategy has achieved tunable doping levels in OSCs with high spatial resolution, which is expected to be highly suited for integrated circuits in both roll-to-roll and laboratory-scale environments.
Conjugated polymers, Electrical and electronic engineering, Electronic devices, Electronic properties and materials
Unconventional solitonic high-temperature superfluorescence from perovskites
Original Paper | Condensed-matter physics | 2025-05-27 20:00 EDT
Melike Biliroglu, Mustafa Türe, Antonia Ghita, Myratgeldi Kotyrov, Xixi Qin, Dovletgeldi Seyitliyev, Natchanun Phonthiptokun, Malek Abdelsamei, Jingshan Chai, Rui Su, Uthpala Herath, Anna K. Swan, Vasily V. Temnov, Volker Blum, Franky So, Kenan Gundogdu
Fast thermal dephasing limits macroscopic quantum phenomena to cryogenic conditions1,2,3,4 and hinders their use at ambient temperatures5,6. For electronic excitations in condensed media, dephasing is mediated by thermal lattice motion1,7,8. Therefore, taming the lattice influence is essential for creating collective electronic quantum states at high temperatures. Although there are occasional reports of high-Tc quantum effects across different platforms, it is unclear which lattice characteristics and electron-lattice interactions lead to macroscopically coherent electronic states in solids9. Here we studied intensity fluctuations in the macroscopic polarization during the emergence of superfluorescence in a lead halide perovskite10 and showed that spontaneously synchronized polaronic lattice oscillations accompany collective electronic dipole emission. We further developed an effective field model and theoretically confirmed that exciton-lattice interactions lead to a new electronically and structurally entangled coherent extended solitonic state beyond a critical polaron density. The analysis shows a phase transition with two processes happening in tandem: incoherent disordered polaronic lattice deformations establish an order, while macroscopic quantum coherence among excitons simultaneously emerges. Recombination of excitons in this state culminates in superfluorescence at high temperatures. Our study establishes fundamental connections between the transient superfluorescence process observed after the impulsive excitation of perovskites and general equilibrium phase transitions achieved by thermal cooling. By identifying various electron-lattice interactions in the perovskite structure and their respective role in creating collectively coherent electronic effects in solids, our work provides unprecedented insight into the design and development of new materials that exhibit high-temperature macroscopic quantum phenomena.
Condensed-matter physics, Lasers, LEDs and light sources, Phase transitions and critical phenomena, Quantum optics
Observing anyonization of bosons in a quantum gas
Original Paper | Bose-Einstein condensates | 2025-05-27 20:00 EDT
Sudipta Dhar, Botao Wang, Milena Horvath, Amit Vashisht, Yi Zeng, Mikhail B. Zvonarev, Nathan Goldman, Yanliang Guo, Manuele Landini, Hanns-Christoph Nägerl
Anyons1,2 are low-dimensional quasiparticles that obey fractional statistics, hence interpolating between bosons and fermions. In two dimensions, they exist as elementary excitations of fractional quantum Hall states3,4,5 and are believed to enable topological quantum computing6,7. One-dimensional anyons have been theoretically proposed, but their experimental realization has proven to be difficult. Here we observed emergent anyonic correlations in a one-dimensional strongly interacting quantum gas, resulting from the phenomenon of spin-charge separation8,9,10. A mobile impurity provides the necessary spin degree of freedom to engineer anyonic correlations in the charge sector and simultaneously acts as a probe to reveal these correlations. Starting with bosons, we tune the statistical phase to transmute bosons through anyons to fermions and observe an asymmetric momentum distribution11,12,13,14, a hallmark of anyonic correlations. Going beyond equilibrium conditions, we observed dynamical fermionization of the anyons15. This study opens the door to the exploration of non-equilibrium anyonic phenomena in a highly controllable setting15,16,17.
Bose-Einstein condensates, Quantum fluids and solids, Quantum mechanics, Quantum simulation
EndoMAP.v1 charts the structural landscape of human early endosome complexes
Original Paper | Endosomes | 2025-05-27 20:00 EDT
Miguel A. Gonzalez-Lozano, Ernst W. Schmid, Enya Miguel Whelan, Yizhi Jiang, Joao A. Paulo, Johannes C. Walter, J. Wade Harper
Early or sorting endosomes are dynamic organelles that play key roles in proteome control by triaging plasma membrane proteins for either recycling or degradation in the lysosome1,2. These events are coordinated by numerous transiently associated regulatory complexes and integral membrane components that contribute to organelle identity during endosome maturation3. Although a subset of the several hundred protein components and cargoes known to associate with endosomes have been studied at the biochemical and/or structural level, interaction partners and higher-order molecular assemblies for many endosomal components remain unknown. Here, we combine crosslinking and native gel mass spectrometry4,5,6,7 of purified early endosomes with AlphaFold8,9 and computational analysis to create a systematic human endosomal structural interactome. We present 229 structural models for endosomal protein pairs and additional higher-order assemblies supported by experimental crosslinks from their native subcellular context, suggesting structural mechanisms for previously reported regulatory processes. Using induced neurons, we validate two candidate complexes whose interactions are supported by crosslinks and structural predictions: TMEM230 as a subunit of ATP8 and ATP11 lipid flippases10 and TMEM9 and TMEM9B as subunits of the chloride-proton antiporters CLCN3, CLCN4 and CLCN5 (ref. 11). This resource and its accompanying structural network viewer provide an experimental framework for understanding organellar structural interactomes and large-scale validation of structural predictions.
Endosomes, Proteomics
Dynamic basal ganglia output signals license and suppress forelimb movements
Original Paper | Basal ganglia | 2025-05-27 20:00 EDT
Antonio Falasconi, Harsh Kanodia, Silvia Arber
The basal ganglia are fundamental to motor control and their dysfunction is linked to motor deficits1,2,3,4,5,6,7,8. Influential investigations on the primate oculomotor system posited that movement generally depends on transient pauses of tonically firing inhibitory basal ganglia output neurons releasing brainstem motor centres9,10. However, prominent increases in basal ganglia output neuron firing observed during other motor tasks cast doubts on the proposed mechanisms of movement regulation through basal ganglia circuitry11,12,13,14,15,16,17,18,19,20,21,22. Here we show that basal ganglia output neurons in the mouse substantia nigra pars reticulata (SNr) represent complex forelimb movements with highly granular and dynamic changes in spiking activity, tiling task execution at the population level. Single SNr neurons exhibit movement-specific firing pauses as well as increases, each occurring in concert with precise and different forelimb movements. Combining optogenetics and simultaneous recordings from basal ganglia output and postsynaptic brainstem neurons, we reveal the functional role of these dynamic firing-rate changes in releasing and suppressing movement through downstream targets. Together, our results demonstrate the existence and function of highly specific and temporally precise movement representations in basal ganglia output circuitry. We propose a model in which basal ganglia output neurons fire dynamically to provide granular and bidirectional movement-specific signals for release and suppression of motor programs to downstream circuits.
Basal ganglia, Neural circuits
The pivot penalty in research
Original Paper | Careers | 2025-05-27 20:00 EDT
Ryan Hill, Yian Yin, Carolyn Stein, Xizhao Wang, Dashun Wang, Benjamin F. Jones
Scientists and inventors set the direction of their work amid evolving questions, opportunities and challenges, yet the understanding of pivots between research areas and their outcomes remains limited1,2,3,4,5. Theories of creative search highlight the potential benefits of exploration but also emphasize difficulties in moving beyond one’s expertise6,7,8,9,10,11,<a data-test=”citation-ref” data-track=”click” data-track-action=”reference anchor” data-track-label=”link” href=”https://www.nature.com/articles/s41586-025-09048-1#ref-CR12“ id=”ref-link-section-d23849750e519_6” title=”Jones, B. F. The burden of knowledge and the “death of the renaissance man”: is innovation getting harder? Rev. Econ. Stud. 76, 283-317 (2009).”>12,13,14. Here we introduce a measurement framework to quantify how far researchers move from their existing work, and apply it to millions of papers and patents. We find a pervasive ‘pivot penalty’, in which the impact of new research steeply declines the further a researcher moves from their previous work. The pivot penalty applies nearly universally across science and patenting, and has been growing in magnitude over the past five decades. Larger pivots further exhibit weak engagement with established mixtures of prior knowledge, lower publication success rates and less market impact. Unexpected shocks to the research landscape, which may push researchers away from existing areas or pull them into new ones, further demonstrate substantial pivot penalties, including in the context of the COVID-19 pandemic. The pivot penalty generalizes across fields, career stage, productivity, collaboration and funding contexts, highlighting both the breadth and depth of the adaptive challenge. Overall, the findings point to large and increasing challenges in effectively adapting to new opportunities and threats, with implications for individual researchers, research organizations, science policy and the capacity of science and society as a whole to confront emergent demands.
Careers, Research management
The subfornical organ is a nucleus for gut-derived T cells that regulate behaviour
Original Paper | Neuroimmunology | 2025-05-27 20:00 EDT
Tomomi M. Yoshida, Mytien Nguyen, Le Zhang, Benjamin Y. Lu, Biqing Zhu, Katie N. Murray, Yann S. Mineur, Cuiling Zhang, Di Xu, Elizabeth Lin, Joseph Luchsinger, Sagar Bhatta, Daniel A. Waizman, Mackenzie E. Coden, Yifan Ma, Kavita Israni-Winger, Anthony Russo, Haowei Wang, Wenzhi Song, Jafar Al Souz, Hongyu Zhao, Joseph E. Craft, Marina R. Picciotto, Jaime Grutzendler, Marcello Distasio, Noah W. Palm, David A. Hafler, Andrew Wang
Specialized immune cells that reside in tissues orchestrate diverse biological functions by communicating with parenchymal cells1. The contribution of the innate immune compartment in the meninges and the central nervous system (CNS) is well-characterized; however, whether cells of the adaptive immune system reside in the brain and are involved in maintaining homeostasis is unclear2,3,4. Here we show that the subfornical organ (SFO) of the brain is a nucleus for parenchymal αβ T cells in the steady-state brain in both mice and humans. Using unbiased transcriptomics, we show that these extravascular T cells in the brain are distinct from meningeal T cells: they secrete IFNγ robustly and express tissue-residence proteins such as CXCR6, which are required for their retention in the brain and for normal adaptive behaviour. These T cells are primed in the periphery by the microbiome, and traffic from the white adipose and gastrointestinal tissues to the brain. Once established, their numbers can be modulated by alterations to either the gut microbiota or the composition of adipose tissue. In summary, we find that CD4 T cells reside in the brain at steady state and are anatomically concentrated in the SFO in mice and humans; that they are transcriptionally and functionally distinct from meningeal T cells; and that they secrete IFNγ to maintain CNS homeostasis through homeostatic fat-brain and gut-brain axes.
Neuroimmunology, Physiology
The history and future of resting-state functional magnetic resonance imaging
Review Paper | Cognitive neuroscience | 2025-05-27 20:00 EDT
Bharat B. Biswal, Lucina Q. Uddin
Since the discovery of resting-state functional connectivity in the human brain, this neuroimaging approach has revolutionized the study of neural architecture. Once considered noise, the functional significance of spontaneous low-frequency fluctuations across large-scale brain networks has now been investigated in more than 25,000 publications. In this Review, we provide a historical overview and thoughts regarding potential future directions for resting-state functional MRI (rsfMRI) research, highlighting the most informative analytic approaches that have been developed to reveal the brain’s intrinsic spatiotemporal organization. We review the collaborative efforts that have led to the widespread use of rsfMRI in neuroscience, with an emphasis on methodological innovations that have been made possible by contributions from electrical and biomedical engineering, physics, mathematics and computer science. We focus on key theoretical and methodological advances that will be necessary for further progress in the field, highlighting the need for further integration with new developments in whole-brain computational modelling, more sophisticated approaches to brain-behaviour mapping, greater mechanistic insights from concurrent measurement of neurophysiology, and greater appreciation of the problem of generalization failure in machine learning applications. We propose that rsfMRI has the potential for even greater clinical relevance when it is fully integrated with population neuroscience and global health initiatives in the service of precision psychiatry.
Cognitive neuroscience, Neuro-vascular interactions
Global dominance of seasonality in shaping lake-surface-extent dynamics
Original Paper | Hydrology | 2025-05-27 20:00 EDT
Luoqi Li, Di Long, Yiming Wang, R. Iestyn Woolway
Lakes are crucial for ecosystems1, greenhouse gas emissions2 and water resources3, yet their surface-extent dynamics, particularly seasonality, remain poorly understood at continental to global scales owing to limitations in satellite observations4,5. Although previous studies have focused on long-term changes6,7,8, comprehensive assessments of seasonality have been constrained by trade-offs between spatial resolution and temporal resolution in single-source satellite data. Here we show that seasonality is the dominant driver of lake-surface-extent variations globally. By leveraging a deep-learning-based spatiotemporal fusion of MODIS and Landsat-based datasets, combined with high-performance computing, we achieved monthly mapping of 1.4 million lakes (2001-2023). Our approach yielded basin-level median user’s and producer’s accuracies of 93% and 96%, respectively, when validated against the Global Surface Water dataset7. Seasonality-dominated lakes constitute 66% of the global lake area and approximately 60% of total lake counts, with over 90% of the world’s population residing in regions where such lakes prevail. During seasonality-induced extreme events, the impacts can exceed the combined magnitude of 23-year long-term changes and regular seasonal variations, doubling the contraction of 42% of shrinking lakes and fully offsetting the expansion of 45% of growing lakes. These results uncover previously hidden seasonal dynamics that are crucial for understanding hydrospheric responses to environmental changes9, protecting lacustrine systems10,11,12 and improving global climate models13,14. Our findings underscore the importance of incorporating seasonality into future research and suggest that advancements in the fusion of multisource remote-sensing data offer a promising path forward.
Hydrology
Domesticated cannabinoid synthases amid a wild mosaic cannabis pangenome
Original Paper | Molecular evolution | 2025-05-27 20:00 EDT
Ryan C. Lynch, Lillian K. Padgitt-Cobb, Andrea R. Garfinkel, Brian J. Knaus, Nolan T. Hartwick, Nicholas Allsing, Anthony Aylward, Philip C. Bentz, Sarah B. Carey, Allen Mamerto, Justine K. Kitony, Kelly Colt, Emily R. Murray, Tiffany Duong, Heidi I. Chen, Aaron Trippe, Alex Harkess, Seth Crawford, Kelly Vining, Todd P. Michael
Cannabis sativa is a globally important seed oil, fibre and drug-producing plant species. However, a century of prohibition has severely restricted development of breeding and germplasm resources, leaving potential hemp-based nutritional and fibre applications unrealized. Here we present a cannabis pangenome, constructed with 181 new and 12 previously released genomes from a total of 144 biological samples including both male (XY) and female (XX) plants. We identified widespread regions of the cannabis pangenome that are surprisingly diverse for a single species, with high levels of genetic and structural variation, and propose a novel population structure and hybridization history. Across the ancient heteromorphic X and Y sex chromosomes, we observed a variable boundary at the sex-determining and pseudoautosomal regions as well as genes that exhibit male-biased expression, including genes encoding several key flowering regulators. Conversely, the cannabinoid synthase genes, which are responsible for producing cannabidiol acid and delta-9-tetrahydrocannabinolic acid, contained very low levels of diversity, despite being embedded within a variable region with multiple pseudogenized paralogues, structural variation and distinct transposable element arrangements. Additionally, we identified variants of acyl-lipid thioesterase genes that were associated with fatty acid chain length variation and the production of the rare cannabinoids, tetrahydrocannabivarin and cannabidivarin. We conclude that the C. sativa gene pool remains only partially characterized, the existence of wild relatives in Asia is likely and its potential as a crop species remains largely unrealized.
Molecular evolution, Natural variation in plants, Plant breeding, Plant evolution, Transposition
Electrical switching of a p-wave magnet
Original Paper | Ferroelectrics and multiferroics | 2025-05-27 20:00 EDT
Qian Song, Srdjan Stavrić, Paolo Barone, Andrea Droghetti, Daniil S. Antonenko, Jörn W. F. Venderbos, Connor A. Occhialini, Batyr Ilyas, Emre Ergeçen, Nuh Gedik, Sang-Wook Cheong, Rafael M. Fernandes, Silvia Picozzi, Riccardo Comin
Magnetic states with zero magnetization but non-relativistic spin splitting are outstanding candidates for the next generation of spintronic devices. Their electronvolt (eV)-scale spin splitting, ultrafast spin dynamics and nearly vanishing stray fields make them particularly promising for several applications1,2. A variety of such magnetic states with non-trivial spin textures have been identified recently, including even-parity d-wave, g-wave or i-wave altermagnets and odd-parity p-wave magnets3,4,5,6,7. Achieving voltage-based control of the non-uniform spin polarization of these magnetic states is of great interest for realizing energy-efficient and compact devices for information storage and processing8,9. Spin-spiral type II multiferroics are optimal candidates for such voltage-based control, as they exhibit an inversion-symmetry-breaking magnetic order that directly induces ferroelectric polarization, allowing for symmetry-protected cross-control between spin chirality and polar order10,11,12,13,14. Here we combine photocurrent measurements, first-principles calculations and group-theory analysis to provide direct evidence that the spin polarization of the spin-spiral type II multiferroic NiI2 exhibits odd-parity character connected to the spiral chirality. The symmetry-protected coupling between chirality and polar order enables electrical control of a primarily non-relativistic spin polarization. Our findings represent an observation of p-wave magnetism in a spin-spiral type II multiferroic, which may lead to the development of voltage-based switching of non-relativistic spin polarization in compensated magnets.
Ferroelectrics and multiferroics, Spintronics
Nature Materials
Hyper-gap transparent conductor
Original Paper | Materials for optics | 2025-05-27 20:00 EDT
Zhengran Wu, Chunhong Li, Xiaolei Hu, Kun Chen, Xiang Guo, Yan Li, Ling Lu
An elusive conductor with perfect optical transparency holds revolutionary potential for fields such as optoelectronics and nanophotonics. Such a hypothetical metal would possess a spectral gap1,2–a ‘hyper-gap’–in its absorption spectrum, separating the intraband and interband absorptions, in which optical losses could vanish. Currently, this property is achievable only within the bandgap of insulators. However, realizing such a hyper-gap metal demands an exotic electronic structure in which the conducting bands have a bandwidth narrower than their energy separations from the remaining electronic states. Here we present such a hyper-gap in a family of organic metals–the Fabre charge-transfer salts3–through first-principles predictions coupled with both electrical and optical measurements. A transparent window, spanning from red to near-infrared wavelengths, is identified in bulk single crystals that remain transmissive over a thickness of 30 µm. The corresponding absorption coefficient is the lowest among known stoichiometric metals, rivalling thin films of transparent conductive oxides. This finding introduces a path, beyond traditional doping strategies in insulators, to combine electronic conduction and optical transparency.
Materials for optics, Optical materials and structures
Nature Nanotechnology
Application-driven design of non-aqueous electrolyte solutions through quantification of interfacial reactions in lithium metal batteries
Original Paper | Batteries | 2025-05-27 20:00 EDT
Hansen Wang, Xiaolin Yan, Rupeng Zhang, Juanjuan Sun, Fuxiang Feng, Haoran Li, Jinding Liang, Yuchun Wang, Guangzhou Ye, Xiaonan Luo, Shengyuan Huang, Pan Wan, Samantha T. Hung, Fangjun Ye, Fangyun Chen, Erxiao Wu, Jinfei Zhou, Ulderico Ulissi, Xiaoming Ge, Chengyong Liu, Bo Xu, Na Liu, Chuying Ouyang
Unwanted side reactions occurring at electrode|electrolyte interfaces significantly impact the cycling life of lithium metal batteries. However, a comprehensive view that rationalizes these interfacial reactions and assesses them both qualitatively and quantitatively is not yet established. Here, by combining multiple analytical techniques, we systematically investigate the interfacial reactions in lithium metal batteries containing ether-based non-aqueous electrolyte solutions. We quantitatively monitor various nanoscale-driven processes such as the reduction and oxidation pathways of lithium salt and organic solvents, the formation of various solid-electrolyte interphase species, the gas generation within the cell and the cross-talk processes between the electrodes. We demonstrate that the consumption of lithium ions owing to the continuous decomposition of the lithium bis(fluorosulfonyl)imide salt, which dominates the interfacial reactions, results in ion depletion during the cell discharge and battery failure. On the basis of these findings, we propose an electrolyte formulation in which lithium bis(fluorosulfonyl)imide content is maximized without compromising dynamic viscosity and bulk ionic conductivity, aiming for long-cycling battery performance. Following this strategy, we assemble and test Li (20 μm thickness)||LiNi0.8Mn0.1Co0.1O2 (17.1 mg cm-2 of active material) single-layer stack pouch cells in lean electrolyte conditions (that is, 2.1 g Ah-1), which can effectively sustain 483 charge (0.2 C or 28 mA)/discharge (1 C or 140 mA) cycles at 25 °C demonstrating a discharge capacity retention of about 77%.
Batteries, Electrochemistry, Energy storage, Materials for energy and catalysis, Techniques and instrumentation
Physical Review Letters
Quantum Decoherence from Complex Saddle Points
Research article | Open quantum systems & decoherence | 2025-05-27 06:00 EDT
Jun Nishimura and Hiromasa Watanabe
Quantum decoherence is the effect that bridges quantum physics to well-understood classical physics. As such, it plays a crucial role in understanding the mysterious nature of quantum physics. Quantum decoherence is also a source of quantum noise that has to be well under control in quantum computing and in various experiments based on quantum technologies. Here we point out that quantum decoherence can be captured by complex saddle points in the Feynman path integral in much the same way as quantum tunneling can be captured by instantons. In particular, we present some first-principle calculations in the Caldeira–Leggett model, which reproduce the predicted scaling behavior of quantum decoherence with respect to the parameters of the environment such as the temperature and the coupling to the system of interest. We also discuss how to extend our approach to general models by Monte Carlo calculations using a recently developed method to overcome the sign problem.
Phys. Rev. Lett. 134, 210401 (2025)
Open quantum systems & decoherence, Quantum coherence & coherence measures, Path-integral methods
Data Driven Approach for Extracting Tidal Information from Neutron Star Binary Mergers Observed with the Einstein Telescope
Research article | Gravitational wave detection | 2025-05-27 06:00 EDT
Adrian Abac, Anna Puecher, Jonathan Gair, and Tim Dietrich
The recent breakthroughs regarding the detection of compact binary mergers via gravitational waves opened up a new window to the Universe. Gravitational-wave models have been essential to this success since they are necessary to infer the properties of the compact binary system from the observational data. Next-generation detectors, such as the Einstein Telescope, will allow for more observations of binary neutron star mergers with higher precision, making accurate waveform models crucial in describing these systems. In this Letter, we propose a novel approach for constructing phenomenological waveform models informed by observational data. Using mock data representing a one-year operation of the Einstein telescope as our baseline, we demonstrate how the results improve as more events are included in the calibration. This method offers a new and complementary approach for developing sophisticated gravitational-wave models compared to classical techniques that employ analytical computations and numerical-relativity simulations. Improved waveform models will then yield more accurate parameter estimation.
Phys. Rev. Lett. 134, 211401 (2025)
Gravitational wave detection, Gravitational waves, Neutron stars & pulsars
Inequivalence between the Euclidean and Lorentzian Versions of the Type IIB Matrix Model from Lefschetz Thimble Calculations
Research article | Lower-dimensional field theories | 2025-05-27 06:00 EDT
Chien-Yu Chou, Jun Nishimura, and Ashutosh Tripathi
The type IIB matrix model is conjectured to describe superstring theory nonperturbatively in terms of ten $N\times{}N$ bosonic traceless Hermitian matrices ${A}{\mu }$ ($\mu =0,\dots{},9$), whose eigenvalues correspond to ($9+1$)-dimensional space-time. Quite often, this model has been investigated in its Euclidean version, which is well defined although the $\mathrm{SO}(9,1)$ Lorentz symmetry of the original model is replaced by the $\mathrm{SO}(10)$ rotational symmetry. Recently, a well-defined model respecting the Lorentz symmetry has been proposed by ‘’gauge-fixing’’ the Lorentz symmetry nonperturbatively using the Faddeev-Popov procedure. Here we investigate the two models by Monte Carlo simulations overcoming the severe sign problem by the Lefschetz thimble method, in the case of matrix size $N=2$ omitting fermionic contributions. We add a quadratic term $\gamma \mathrm{tr}({A}{\mu }{A}^{\mu })$ in the action and calculate the expectation values of rotationally symmetric (or Lorentz symmetric) observables as a function of the coefficient $\gamma $. Our results exhibit striking differences between the two models around $\gamma =0$ and in the $\gamma >0$ region associated with the appearance of different saddle points, clearly demonstrating their inequivalence against naive expectations from quantum field theory.
Phys. Rev. Lett. 134, 211601 (2025)
Lower-dimensional field theories, Quantum field theory, Strings & branes, Spacetime symmetries, Large-N expansion in field theory, Path-integral Monte Carlo
First Measurement of the Muon Neutrino Interaction Cross Section and Flux as a Function of Energy at the LHC with FASER
Research article | Neutrino interactions | 2025-05-27 06:00 EDT
Roshan Mammen Abraham et al. (FASER Collaboration)
This Letter presents the measurement of the energy-dependent neutrino-nucleon cross section in tungsten and the differential flux of muon neutrinos and antineutrinos. The analysis is performed using proton-proton collision data at a center-of-mass energy of 13.6 TeV and corresponding to an integrated luminosity of $(65.6\pm{}1.4)\text{ }\text{ }{\mathrm{fb}}^{- 1}$. Using the active electronic components of the FASER detector, $338.1\pm{}21.0$ charged current muon neutrino interaction events are identified, with backgrounds from other processes subtracted. We unfold the neutrino events into a fiducial volume corresponding to the sensitive regions of the FASER detector and interpret the results in two ways: (i) we use the expected neutrino flux to measure the cross section, and (ii) we use the predicted cross section to measure the neutrino flux. Both results are presented in six bins of neutrino energy, achieving the first differential measurement in the TeV range. The observed distributions align with standard model predictions. Using this differential data, we extract the contributions of neutrinos from pion and kaon decays.
Phys. Rev. Lett. 134, 211801 (2025)
Neutrino interactions, Neutrinos, Neutrino detection
Unveiling Under-the-Barrier Electron Dynamics in Strong Field Tunneling
Research article | Atomic spectra | 2025-05-27 06:00 EDT
Tsendsuren Khurelbaatar, Michael Klaiber, Suren Sukiasyan, Karen Z. Hatsagortsyan, Christoph H. Keitel, and Dong Eon Kim
Ever since the advent of quantum mechanics, tunneling has been an intriguing topic and consequently extensively studied and utilized. Investigating both theoretically and experimentally the nonadiabatic tunneling in strong-field ionization across a wide range of laser intensities, we unravel under-the-barrier-recollision dynamics leading to Freeman resonances (FR). The under-the-barrier-recollision model, which goes beyond the traditional direct multiphoton transition description, predicts distinct features of FR phenomena that cannot be explained by the existing direct multiphoton transition scenario. Specifically, it predicts (i) the dominance of high-order FR over above-threshold ionization in the photoelectron energy spectra and (ii) the flat dependence of the FR signal on the laser intensity, both in the nonadiabatic tunneling regime. This Letter experimentally demonstrates these features, corroborating the under-the-barrier-recollision model, and provides intuition into this dynamics, expanding our insights into the control of tunneling dynamics in laser spectroscopy and attosecond physics.
Phys. Rev. Lett. 134, 213201 (2025)
Atomic spectra, Electronic excitation & ionization, Single- and few-photon ionization & excitation, Strong field ionization & excitation, Strong-field-induced spectra
Efficient Transverse Multiwave Interactions up to Six-Wave Mixing in a High-Q Lithium Niobate Microresonator
Research article | High-order harmonic generation | 2025-05-27 06:00 EDT
Chuntao Li, Ni Yao, Huakang Yu, Jintian Lin, Renhong Gao, Jiale Deng, Jianglin Guan, Lingling Qiao, and Ya Cheng
Self-organized subwavelength photorefractive gratings formed in high-Q lithium niobate microresonators lead to the first demonstration of efficient transverse nonlinear interactions up to six-wave mixing under single continuous-wave laser pumping.
Phys. Rev. Lett. 134, 213801 (2025)
High-order harmonic generation, Integrated optics, Second order nonlinear optical processes, Stimulated Raman scattering, Microcavity & microdisk lasers, Raman lasers, Tunable lasers
Large Tunable Kinetic Inductance in a Twisted Graphene Superconductor
Research article | Coherence length | 2025-05-27 06:00 EDT
Rounak Jha, Martin Endres, Kenji Watanabe, Takashi Taniguchi, Mitali Banerjee, Christian Schönenberger, and Paritosh Karnatak
The graphene multilayer’s kinetic inductance is both high and tunable, making it a promising material for quantum technologies.
Phys. Rev. Lett. 134, 216001 (2025)
Coherence length, Critical current, Flat bands, Josephson effect, Proximity effect, Quantum interference effects, Superconducting order parameter, Twistronics, Graphene
Machine Learning Small Polaron Dynamics
Research article | Hopping transport | 2025-05-27 06:00 EDT
Viktor C. Birschitzky, Luca Leoni, Michele Reticcioli, and Cesare Franchini
Polarons are crucial for charge transport in semiconductors, significantly impacting material properties and device performance. The dynamics of small polarons can be investigated using first-principles molecular dynamics. However, the limited timescale of these simulations presents a challenge for adequately sampling infrequent polaron hopping events. Here, we introduce a message-passing neural network combined with first-principles molecular dynamics within the Born-Oppenheimer approximation that learns the polaronic potential energy surface by encoding the polaronic state, allowing for simulations of polaron hopping dynamics at the nanosecond scale. By leveraging the statistical significance of the long timescale, our framework can accurately estimate polaron (anisotropic) mobilities and activation barriers in prototypical polaronic oxides across different scenarios (hole polarons in rocksalt MgO and electron polarons in pristine and F-doped rutile ${\mathrm{TiO}}_{2}$) within experimentally measured ranges.
Phys. Rev. Lett. 134, 216301 (2025)
Hopping transport, Polarons, Potential energy surfaces, Oxides, Ab initio molecular dynamics, Deep learning, Density functional theory, Machine learning
Atacamite ${\mathrm{Cu}}{2}\mathrm{Cl}{(\mathrm{OH})}{3}$ in High Magnetic Fields: Quantum Criticality and Dimensional Reduction of a Sawtooth-Chain Compound
Research article | Frustrated magnetism | 2025-05-27 06:00 EDT
L. Heinze, T. Kotte, R. Rausch, A. Demuer, S. Luther, R. Feyerherm, E. L. Q. N. Ammerlaan, U. Zeitler, D. I. Gorbunov, M. Uhlarz, K. C. Rule, A. U. B. Wolter, H. Kühne, J. Wosnitza, C. Karrasch, and S. Süllow
We report an extensive high-field study of atacamite ${\mathrm{Cu}}{2}\mathrm{Cl}{(\mathrm{OH})}{3}$, a material realization of quantum sawtooth chains with weak interchain couplings, in continuous and pulsed magnetic fields up to 58 T. In particular, we have mapped the entropy landscape for fields as high as 35 T and have identified a field-induced quantum critical point at 21.9(1) T for $\mathbf{H}\parallel c$ axis. The quantum critical point separates field regions with and without magnetic order, evidenced by our thermodynamic study and $^{1}\mathrm{H}$ nuclear magnetic resonance spectroscopy, but lies far below full saturation of the magnetization. Corroborated by numerical results using density-matrix renormalization group calculations, we find this behavior associated with a dimensional reduction of the spin system: the sawtooth chain effectively decouples into an antiferromagnetic spin-$1/2$ chain (backbone of the sawtooth chain) in the presence of an exchange field produced by the remaining field-polarized spins.
Phys. Rev. Lett. 134, 216701 (2025)
Frustrated magnetism, High magnetic fields, Phase diagrams, Quantum criticality, 1-dimensional spin chains, Magnetic insulators, Density matrix renormalization group, Magnetization measurements, Nuclear magnetic resonance, Specific heat measurements
Physical Review X
Exciton Self-Trapping in Twisted Hexagonal Boron Nitride homostructures
Research article | Excitons | 2025-05-27 06:00 EDT
Sébastien Roux, Christophe Arnold, Etienne Carré, Alexandre Plaud, Lei Ren, Frédéric Fossard, Nicolas Horezan, Eli Janzen, James H. Edgar, Camille Maestre, Bérangère Toury, Catherine Journet, Vincent Garnier, Philippe Steyer, Takashi Taniguchi, Kenji Watanabe, Cédric Robert, Xavier Marie, François Ducastelle, Annick Loiseau, and Julien Barjon
Twisting two hBN flakes reveals new exciton behavior, including self-trapped excitons with strong exciton-phonon coupling. This twist enhances deep-UV luminescence, offering potential for improved hBN-based LEDs and quantum devices.
Phys. Rev. X 15, 021067 (2025)
Excitons, Interfaces, Layered semiconductors, Semiconductors, Luminescence, Scanning electron microscopy, Time-resolved photoluminescence
“Morphogenetic Action” Principle for 3D Shape Formation by the Growth of Thin Sheets
Research article | Developmental biology | 2025-05-27 06:00 EDT
Dillon J. Cislo, Anastasios Pavlopoulos, and Boris I. Shraiman
A theoretical framework explains how tissues select anisotropic growth to shape structures. Anisotropy reduces necessary variation of growth, predicting patterns similar to biological development and offering insights into morphogenesis.
Phys. Rev. X 15, 021068 (2025)
Developmental biology, Mechanical deformation, Pattern formation
High-Fidelity Electron Spin Gates for Scaling Diamond Quantum Registers
Research article | Quantum gates | 2025-05-27 06:00 EDT
T. Joas, F. Ferlemann, R. Sailer, P. J. Vetter, J. Zhang, R. S. Said, T. Teraji, S. Onoda, T. Calarco, G. Genov, M. M. Müller, and F. Jelezko
A 96% fidelity in two-qubit operations between nitrogen-vacancy centers improves scalability for quantum registers in diamond, advancing its potential as a platform for large-scale, room-temperature quantum computing.
Phys. Rev. X 15, 021069 (2025)
Quantum gates, Qubits
Review of Modern Physics
Quantum physics of stars
Research article | Models & methods for nuclear reactions | 2025-05-27 06:00 EDT
M. Wiescher, C. A. Bertulani, C. R. Brune, R. J. deBoer, A. Diaz-Torres, L. R. Gasques, K. Langanke, P. Navrátil, W. Nazarewicz, J. Okołowicz, D. R. Phillips, M. Płoszajczak, S. Quaglioni, and A. Tumino
There are many nuclear reactions that are of central importance for stellar burning and element formation. In typical stars, these reactions take place at very low energy, and many of them have very small rates, making it difficult to measure them directly in the laboratory. On the theoretical side, the low-energy regime is governed by quantum-mechanical phenomena like tunneling, near-threshold resonances, and interference effects. This review summarizes the state of the art in the theory of low-energy nuclear reactions in stars and describes new ideas for studying these reactions on Earth.
Rev. Mod. Phys. 97, 025003 (2025)
Models & methods for nuclear reactions, Nuclear astrophysics, Nuclear reactions, Nuclear structure & decays
arXiv
Exact solution and Luttinger liquid behavior of the quantum 1D hard rod model
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-28 20:00 EDT
Shengjie Yu, Zhaoxuan Zhu, Laurent Sanchez-Palencia
The quantum hard rod model, a one-dimensional extension of the Lieb-Liniger model, is exactly solved using an adapted Bethe ansatz. Our solution, benchmarked against path-integral quantum Monte Carlo calculations, reveals significant corrections to the excitation spectrum and thermodynamic properties, previously overlooked by the standard excluded-volume approach. We also show that the hard rod model exhibits Luttinger liquid behavior across a wide range of parameters, at zero and finite temperature, as unveiled by correlation functions. This work provides a comprehensive framework for understanding strongly correlated regimes in dilute 1D systems, with applications to quantum wires, spin chains, and ultracold atoms.
Strongly Correlated Electrons (cond-mat.str-el), Quantum Gases (cond-mat.quant-gas), Quantum Physics (quant-ph)
Generalized Hall Conductivities in Local Commuting Projector Models: Generalized Symmetries and Protected Surface Modes
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-28 20:00 EDT
Po-Shen Hsin, Ryohei Kobayashi
Hall conductivities are important characterizations of phases of matter. It is known that nonzero Hall conductivities are difficult to realize in local commuting projector lattice models due to no-go theorems in (2+1)D. In this work we construct local commuting projector models in (2+1)D and (3+1)D with nonzero generalized Hall conductivities for ordinary and higher-form continuous symmetries on tensor product Hilbert space of finite local dimension. The model is given by a standard $ \mathbb{Z}_N$ toric code, but the symmetries do not admit expression in terms of onsite charge operators. The symmetry do not have local charges or currents on the lattice in the absence of boundaries, but there is still notion of Hall conductivities that coincide with the continuum field theories. We construct protected gapless boundaries of the lattice models using modified Villain formalism. The generalized Hall conductivities are computed by surface currents as well as bulk flux insertion and many body Chern number.
Strongly Correlated Electrons (cond-mat.str-el), High Energy Physics - Theory (hep-th), Quantum Physics (quant-ph)
21 pages, 7 figures
Quantized Transport of Disordered Superconducting $ν=2/3$ Fractional Quantum Hall Edges
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-28 20:00 EDT
Pok Man Tam, Hao Chen, Biao Lian
The $ \nu=2/3$ fractional quantum Hall (FQH) edge states, which have counter-propagating modes, are known to flow under relevant neutral disorders into a stable Kane-Fisher-Polchinski (KFP) renormalization group (RG) fixed point, which yields a quantized two-terminal conductance $ \frac{2}{3}\frac{e^2}{h}$ consistent with the experiments. Motivated by growing interests in superconducting (SC) quantum Hall systems, we study the $ \nu=2/3$ FQH edge states with disordered SC proximity by generalizing the KFP analysis, which may also apply to the recently realized $ \nu=2/3$ fractional Chern insulator. We show that the $ \nu=2/3$ FQH edge theory has an infinite number of stable RG fixed points SC$ _N$ labeled by an integer $ N\in\mathbb{Z}$ , each of which is driven by a relevant disordered charge-$ 2q_N$ SC tunneling with $ q_N\in\mathbb{Z}$ depending on $ N$ . The $ N<0$ ($ N\ge0$ ) phases are favored by an attractive (repulsive) inter-mode interaction on the edge. We further predict that the edge states in a SC$ _N$ phase with $ q_N\neq0$ yields a quantized downstream resistance $ R_d=\frac{h}{2q_N^2e^2}$ measurable in a FQH-SC junction. For edge states staying in the KFP phase ($ N=0$ and $ q_N=0$ ) under SC proximity, we arrive at a nonlinear $ R_d\propto V^{-\alpha}$ or $ T^{-\alpha}$ with voltage bias $ V$ or temperature $ T$ , where $ \alpha=4$ ($ \alpha=1$ ) if pairing (vortex tunneling) dominates.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Disordered Systems and Neural Networks (cond-mat.dis-nn), Strongly Correlated Electrons (cond-mat.str-el), Superconductivity (cond-mat.supr-con)
Main: 4.5 pages, 3 figures; Supplemental Material: 5 sections
Casimir effect in critical $\mathrm{O}(N)$ models from non-equilibrium Monte Carlo simulations
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-05-28 20:00 EDT
Andrea Bulgarelli, Michele Caselle, Alessandro Nada, Marco Panero
$ \mathrm{O}(N)$ vector models in three dimensions, when defined in a geometry with a compact direction and tuned to criticality, exhibit long-range fluctuations which induce a Casimir effect. The strength of the resulting interaction is encoded in the excess free-energy density, which depends on a universal coefficient: the Casimir amplitude. We present a high-precision numerical calculation of the latter, by means of a novel non-equilibrium Monte Carlo algorithm, and compare our findings with results obtained from large-$ N$ expansions and from the conformal bootstrap.
Statistical Mechanics (cond-mat.stat-mech), High Energy Physics - Lattice (hep-lat), High Energy Physics - Theory (hep-th)
11 pages, 7 figures
Leveraging recurrence in neural network wavefunctions for large-scale simulations of Heisenberg antiferromagnets: the triangular lattice
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-28 20:00 EDT
M. Schuyler Moss, Roeland Wiersema, Mohamed Hibat-Allah, Juan Carrasquilla, Roger G. Melko
Variational Monte Carlo simulations have been crucial for understanding quantum many-body systems, especially when the Hamiltonian is frustrated and the ground-state wavefunction has a non-trivial sign structure. In this paper, we use recurrent neural network (RNN) wavefunction ansätze to study the triangular-lattice antiferromagnetic Heisenberg model (TLAHM) for lattice sizes up to $ 30\times30$ . In a recent study [M. S. Moss et al. arXiv:2502.17144], the authors have demonstrated how RNN wavefunctions can be iteratively retrained in order to obtain variational results for multiple lattice sizes with a reasonable amount of compute. That study, which looked at the sign-free, square-lattice antiferromagnetic Heisenberg model, showed favorable scaling properties, allowing accurate finite-size extrapolations to the thermodynamic limit. In contrast, our present results illustrate in detail the relative difficulty in simulating the sign-problematic TLAHM. We find that the accuracy of our simulations can be significantly improved by transforming the Hamiltonian with a judicious choice of basis rotation. We also show that a similar benefit can be achieved by using variational neural annealing, an alternative optimization technique that minimizes a pseudo free energy. Ultimately, we are able to obtain estimates of the ground-state properties of the TLAHM in the thermodynamic limit that are in close agreement with values in the literature, showing that RNN wavefunctions provide a powerful toolbox for performing finite-size scaling studies for frustrated quantum many-body systems.
Strongly Correlated Electrons (cond-mat.str-el), Disordered Systems and Neural Networks (cond-mat.dis-nn), Quantum Physics (quant-ph)
20 pages, 15 figures, 5 tables
In situ photoemission study of collective electronic phase transition in VO2-based heterostructures
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-28 20:00 EDT
D. Shiga (1 and 2), S. Inoue (1), T. Kanda (1), N. Hasegawa (1), M. Kitamura (2), K. Horiba (2), K. Yoshimatsu (1), A. F. Santander-Syro (3), H. Kumigashira (1 and 2) ((1) Tohoku University, Sendai, Japan, (2) KEK, Tsukuba, Japan, (3) Université Paris-Saclay, France)
We investigated the origin of collective electronic phase transitions induced at the heterointerface between monoclinic insulating (MI) VO2 and rutile metallic (RM) electron-doped VO2 layers using in situ soft x-ray photoelectron spectroscopy (SXPES) on nanoscale VO2/V0.99W0.01O2 (001)R bilayers. Thanks to the surface sensitivity of SXPES, we determined the changes in the electronic structure and V-V dimerization in each constituent layer separately. The selective observation of the electronic and crystal structures in the upper VO2 layer of the bilayer indicates that the MI-phase VO2 layer undergoes a transition to the RM phase by forming the heterointerface. Detailed temperature-dependent measurements reveal that the RM-phase VO2 undergoes a transition to the MI phase with a decrease in temperature, as in the case of a VO2 single-layer film. Furthermore, during the temperature-induced phase transition in the VO2 layer, the spectra are well described by an in-plane phase separation of the RM and MI phases. These results suggest that the interface-induced transition from the MI phase to the RM phase in the VO2 layer of bilayers occurs as a collective phase transition derived from the static energy balance between the interfacial energy and the bulk free energies of the constituent layers.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
27 pages (including 8-page Supplemental Material), 4 figures in main text and 6 in Supplement. Submitted to Physical Review Materials. Corresponding author: D. Shiga (dshiga@tohoku.this http URL)
Parasitic RF-SQUIDs in superconducting qubits due to wirebonds
New Submission | Superconductivity (cond-mat.supr-con) | 2025-05-28 20:00 EDT
B. Berlitz, E. Daum, S. Deck, A.V. Ustinov, J. Lisenfeld
Superconducting qubits show great promise to realize practical quantum computers from micro-fabricated integrated circuits. However, their solid-state architecture bears the burden of parasitic modes in qubit materials and the control circuitry which cause decoherence and interfere with qubits. Here, we present evidence that wirebonds, which are used to contact the micro-circuits and to realize chip-to-chip airbridges, may contain parasitic Josephson junctions. In our experiment, such a junction was enclosed in a superconducting loop and so gave rise to the formation an RF-SQUID which interfered with a nearby flux-tunable transmon qubit. Periodic signatures observed in magnetic field sweeps revealed a strong AC-dispersive coupling of the parasitic RF-SQUID to both the qubit and its readout resonator, in addition to the DC-inductive coupling between RF-SQUID and qubit. Our finding sheds light on a previously unknown origin of decoherence due to parasitic Josephson junctions in superconducing circuits.
Superconductivity (cond-mat.supr-con), Quantum Physics (quant-ph)
From Chern to Winding: Topological Invariant Correspondence in the Reduced Haldane Model
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-28 20:00 EDT
Ghassan Al-Mahmood, Mohsen Amini, Ebrahim Ghanbari-Adivi, Morteza Soltani
We present an exact analytical investigation of the topological properties and edge states of the Haldane model defined on a honeycomb lattice with zigzag edges. By exploiting translational symmetry along the ribbon direction, we perform a dimensional reduction that maps the two-dimensional model into a family of effective one-dimensional systems parametrized by the crystal momentum $ k_x$ . Each resulting one-dimensional Hamiltonian corresponds to an extended Su-Schrieffer-Heeger (SSH) model with momentum-dependent hoppings and onsite potentials. We introduce a natural rotated basis in which the Hamiltonian becomes planar and the winding number ($ \nu$ ) is directly computable, providing a clear topological characterization of the reduced model. This framework enables us to derive closed-form expressions for the edge-state wavefunctions and their dispersion relations across the full Brillouin zone. We show that the $ \nu$ exactly reproduces the Chern number of the parent model in the topologically nontrivial phase and allows for an exact characterization of the edge modes. Analytical expressions for the edge-state wavefunctions and their dispersion relations are derived without requiring perturbative methods. Our analysis further reveals the critical momentum $ k_c $ where edge states traverse the bulk energy gap, and establishes precise conditions for the topological phase transition. In contrast to earlier models, such as plaquette-based tight-binding reductions, our method reveals hidden geometric symmetries in the extended SSH structure that are essential for understanding the topological behavior of systems with long-range hopping. Our findings offer new insight into the topological features of zigzag nanoribbons and establish a robust framework for analyzing analogous systems.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
All fractional Shapiro steps in the RSJ model with two Josephson harmonics
New Submission | Superconductivity (cond-mat.supr-con) | 2025-05-28 20:00 EDT
Synchronization between the internal dynamics of the superconducting phase in a Josephson junction (JJ) and an external ac signal is a fundamental physical phenomenon, manifesting as constant-voltage Shapiro steps in the current-voltage characteristic. Mathematically, this phase-locking effect is captured by the Resistively Shunted Junction (RSJ) model, an important example of a nonlinear dynamical system. The standard RSJ model considers an overdamped JJ with a sinusoidal (single-harmonic) current-phase relation (CPR) in the current-driven regime with a monochromatic ac component. While this model predicts only integer Shapiro steps, the inclusion of higher Josephson harmonics is known to generate fractional Shapiro steps. In this paper, we show that only two Josephson harmonics in the CPR are sufficient to produce all possible fractional Shapiro steps within the RSJ framework. Using perturbative methods, we analyze amplitudes of these fractional steps. Furthermore, by introducing a phase shift between the two Josephson harmonics, we reveal an asymmetry between positive and negative fractional steps - a signature of the Josephson diode effect.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Mathematical Physics (math-ph), Dynamical Systems (math.DS)
16 pages, 2 figures
Atomic-scale ultrafast dynamics of local charge order in a THz-induced metastable state of 1T-TaS2
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-28 20:00 EDT
Luis E. Parra López, Alkisti Vaitsi, Vivien Sleziona, Fabian Schulz, Martin Wolf, Melanie Müller
Light-induced control of quantum materials enables manipulation of electronic and structural phases on ultrafast timescales. Probing their atomic-scale dynamics is essential to understand the role of defects and domain boundaries, but conventional time-resolved techniques lack the required spatial resolution. Here, we use terahertz (THz) scanning tunneling microscopy to investigate a THz-light-induced metastable state near a defect in 1T-TaS2, and follow its photoinduced dynamics in real space and time. THz excitation induces quasi-stationary changes in the insulating gap on angstrom scales, which we associate with interlayer stacking changes. Simultaneously, THz-lightwave-driven tunneling provides access to ultrafast dynamics of the metastable state, revealing 2.5 THz oscillations of the charge density wave amplitude mode and a 1.3 THz mode attributed to an interlayer shear vibration emerging near the defect. Our results demonstrate the dual role of tip-enhanced THz fields in driving metastability and ultrafast tunneling, opening new avenues for ultrafast atomic-scale control of quantum materials.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
29 pages, 5 figures, 7 supplementary figures
Metallic layered materials with magnetic frustration: An ARPES view of the SmAuAl$_4$Ge$_2$ and TbAuAl$_4$Ge$_2$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-28 20:00 EDT
P. Rezende-Gonçalves, A. Antezak, T. Kato, K. Feng, F. Fortuna, P. Le Fèvre, M. Rosmus, N. Olszowska, T. Sobol, D. J. Singh, R. E. Baumbach, A. F. Santander-Syro, E. Frantzeskakis
Compounds of the new materials class LnTAl$ _4$ X$ _2$ (Ln = lanthanide, X = tetrel, T = transition metal) host exotic magnetic phenomena due to geometric frustration induced by their triangular lattice. Complex spin arrangements, magnetic fluctuations and double magnetic transitions have been well observed by means of magneto-transport. Nevertheless, the experimental electronic structure of this family of materials has been poorly studied. We have investigated the experimental electronic structure of two members of this class of materials: SmAuAl$ _4$ Ge$ _2$ and TbAuAl$ _4$ Ge$ _2$ . By means of Angle-Resolved PhotoEmission Spectroscopy (ARPES) accompanied by Density Functional Theory calculations (DFT), we reveal common trends and features, the important effect of localized spin moments on the electronic structure, the presence of surface-localized electronic states and the nature of the surface termination layer. Low-dimensionality, exchange interaction, and spin-orbit coupling are all important ingredients of the electronic structure.
Strongly Correlated Electrons (cond-mat.str-el)
11 pages, 5 figures
Phys. Rev. B 111, 205114 (2025)
Static and Dynamics of Twisted Skyrmion Tubes in Frustrated Magnets
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-28 20:00 EDT
Carlos Saji, Eduardo Saavedra, Vagson L. Carvalho-Santos, Alvaro S. Nunez, Roberto E. Troncoso
Stable three-dimensional topological skyrmion structures in frustrated magnets are investigated. The texture exhibits a helicoid pattern along the vertical direction, described by a position-dependent helicity, which interpolates between Neel- and hedgehog-like two-dimensional skyrmions, characterized by the Hopf index, and is referred to as “twisted skyrmion tubes” (TSkTs). The stability and topology of TSkTs are achieved by competing next-nearest-neighbor exchange interactions, the thickness of the magnet, and the applied magnetic field. The dynamical behavior of a twisted structure in frustrated magnets is determined. Specifically, we derive that the helicity dynamics of the TSkT can be driven by an electric current resulting from spin-orbit torque interaction. Furthermore, we address the study of the electronic scattering problem using a spin-orbit-torque-driven TSKT, which offers promising applications for low-power storage nanodevices and nanobatteries with enhanced control.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)
7 pages, 4 figures, and a supplemental material
Phase Doubling and Entanglement in Coherent Many-Body Chemical Reactions
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-05-28 20:00 EDT
Shu Nagata, Tadej Meznarsic, Chuixin Kong, Cheng Chin
In the quantum degenerate regime, atoms and molecules can occupy a single quantum state, forming coherent matter waves. Here reactions are described by nonlinear mixing of the matter waves, giving rise to quantum many-body chemistry, where spatial coherence is preserved between the reactants and products. While the phase matching of matter waves during the reaction process has been theoretically predicted, experimental confirmation has remained elusive. Here we report on the observation of matter wave phase doubling when bosonic atoms pair into molecules. Using matter wave diffraction, we verify spatial phase coherence and observe a two-fold increase of phase in the molecular wavefunction, confirming the matter-wave version of phase doubling. The diffraction patterns also reveal non-classical correlations indicative of entangled atom pairs formed during the reaction. Our results establish molecular matter-wave diffraction as a powerful tool to probe quantum coherence and entanglement generation in chemically reactive quantum gases.
Quantum Gases (cond-mat.quant-gas), Atomic Physics (physics.atom-ph), Quantum Physics (quant-ph)
16 pages, 6 figures
Proximity engineering and interferometric quantification of a non-volatile anomalous phase-shift in zero-field polarity-reversible Josephson diodes
New Submission | Superconductivity (cond-mat.supr-con) | 2025-05-28 20:00 EDT
Kun-Rok Jeon, Jae-Keun Kim, Jiho Yoon, Jae-Chun Jeon, Hyeon Han, Audrey Cottet, Takis Kontos, Stuart S. P. Parkin
The recent realization of zero-field polarity-reversible supercurrent rectification in proximity-magnetized Rashba(-type) Pt Josephson junctions (JJs)5 promises its practical applications for superconducting logic circuits and cryogenic memories. Here, by substituting the Pt Josephson barrier for either 5d or 4d element proximity layer with different (para-)magnetic susceptibility, spin-orbit coupling and electronic band structure, we identify the proximity role of the Josephson barrier in determining the zero-field diode properties. Ta (W) JJs reveal the zero-field diode efficiency of 17 (5)% at 2 K, slightly (much) smaller than that of the Pt JJs. Notably, the zero-field diode polarity of Ta and W JJs turns out to be opposite to the Pt JJs. Our results, along with a large zero-field diode efficiency found in highly magnetic-susceptible Pd JJs and a non-volatile anomalous phase-shift {\phi}_0 probed by superconducting quantum interferometry, demonstrate the {\phi}_0-tuning of zero-field diode performance via proximity engineering of interface magnetic ordering and Rashba effect.
Superconductivity (cond-mat.supr-con)
24 pages, 4 figures, 6 extended data figures
Nonlinear Transport Signatures of Hidden Symmetry Breaking in a Weyl Altermagnet
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-28 20:00 EDT
Yufei Zhao, Zhiqiang Mao, Binghai Yan
Phase transitions in solids are often accompanied by structural changes, but subtle lattice distortions can remain hidden from conventional crystallographic probes, hindering the identification of the correct order parameters. A case in point is Ca$ _3$ Ru$ _2$ O$ _7$ , a correlated polar ruthenate with well-characterized phase transitions, whose ground state structure has recently become a subject of debate. This uncertainty stems from extremely small atomic displacements ($ \sim$ 0.001 Å) between competing phases, beyond the resolution of X-ray diffraction, neutron scattering, or optical second-harmonic generation. In this work, we propose a method to detect hidden symmetry breaking by leveraging nonlinear transport induced by quantum geometry. We show that Ca$ _3$ Ru$ _2$ O$ _7$ is a Weyl chain semimetal in both phases. The low-symmetry phase, classified as an altermagnet by symmetry, features distorted topological surface states that are asymmetric along the polar ($ b$ ) axis. However, the nonrelativistic spin splitting is too weak ($ \sim$ 0.1 meV) to be resolved directly, regarding the altermagnetism. In contrast, Weyl chains generate a large quantum metric at the Fermi surface, leading to nonlinear conductivities that are orders of magnitude stronger in the low-symmetry phase. A longitudinal nonlinear conductivity along the polar axis emerges exclusively in this phase, providing a sensitive probe to qualitatively distinguish it from the high-symmetry structure and demonstrate the emergence of altermangetism, which is confirmed by a recent experiment. Our work establishes a route for identifying hidden symmetry breaking in complex quantum materials through the interplay of crystal symmetry, topology and nonlinear quantum transport.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
7 pages, 4 figures
A stochastic Stirling engine powered by an active particle
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-05-28 20:00 EDT
Erick Efrain Cote-Valencia, Juan Ruben Gomez-Solano
We investigate a model of a stochastic engine operating cyclically at constant bath temperature, which consists of an overdamped Brownian harmonic oscillator that plays the role of working substance and is elastically coupled to an active particle. Stirling-like cycles are implemented by time-periodic changes of the active particle speed and the potential confining the oscillator. By analyzing its quasistatic and finite-time performance, we distinguish two regimes, which are determined by the relative magnitudes of the persistence time of active particle, the characteristic time of the elastic interaction, and the viscous relaxation time of the working substance. In the quasistatic limit, we derive analytic expressions for the average output work, the mean absorbed heat, and the efficiency, which explicitly involve the ratios of such three time-scales. For sufficiently large finite cycles, the different quantities characterizing the engine performance converge to their quasistatic values. For shorter cycles, the efficiencies are systematically lower, but with positive mean output powers that exhibit a maximum as a function of the cycle duration if the corresponding quasistatic mean work is positive. For sufficiently short cycles or if the quasistatic work is zero, the engine behaves at finite-time as a heat pump with negative power and efficiency.
Statistical Mechanics (cond-mat.stat-mech), Soft Condensed Matter (cond-mat.soft)
6 figures
Majorana Zero Mode Induced by a Screw Dislocation on the Surface of an Iron-based Superconductor
New Submission | Superconductivity (cond-mat.supr-con) | 2025-05-28 20:00 EDT
We propose a simple scenario to describe a dislocation-induced Majorana zero mode on the surface of an iron-based superconductor, using an illustrative model with a cylindrical hole of radius $ R$ perpendicular to its top surface. Topological surface states on the inner surface of the hole form an effective chiral $ p$ -wave superconductor. When the top surface has a perpendicular magnetization, chiral Majorana modes appear near the circular edge of the hole. Since the corresponding wavefunctions obey an antiperiodic boundary condition in the circumferential direction, a Majorana zero mode at zero energy does not appear. However, if a screw dislocation is inserted through the hole, the antiperiodic boundary condition is transformed into a periodic one, resulting in the appearance of a Majorana zero mode. This Majorana zero mode remains in the no-hole limit of $ R \to 0$ . We confirm this scenario by numerical simulation and effective theory. A method of creating a Majorana zero mode in the absence of the surface magnetization is briefly described.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
10 pages, 7 figures
J. Phys. Soc. Jpn. 94, 064706 (2025)
Kinetic Flat-Histogram Simulations of Non-Equilibrium Stochastic Processes with Continuous and Discontinuous Phase Transitions
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-05-28 20:00 EDT
L. M. C. Alencar, T. F. A. Alves, G. A. Alves, F. W. S. Lima, A. Macedo-Filho, R. S. Ferreira
As far as we know, there is no flat-histogram algorithm to sample the stationary distribution of non-equilibrium stochastic processes. The present work addresses this gap by introducing a generalization of the Wang-Landau algorithm, applied to non-equilibrium stochastic processes with local transitions. The main idea is to sample macroscopic states using a kinetic Monte Carlo algorithm to generate trial moves, which are accepted or rejected with a probability that depends inversely on the stationary distribution. The stationary distribution is refined through the simulation by a modification factor, leading to convergence toward the true stationary distribution. A visitation histogram is also accumulated, and the modification factor is updated when the histogram satisfies a flatness condition. The stationary distribution is obtained in the limit where the modification factor reaches a threshold value close to unity. To test the algorithm, we compare simulation results for several stochastic processes with theoretically known behavior. In addition, results from the kinetic flat-histogram algorithm are compared with standard exact stochastic simulations. We show that the kinetic flat-histogram algorithm can be applied to phase transitions in stochastic processes with bistability, which describe a wide range of phenomena such as epidemic spreading, population growth, chemical reactions, and consensus formation. With some adaptations, the kinetic flat-histogram algorithm can also be applied to stochastic models on lattices and complex networks.
Statistical Mechanics (cond-mat.stat-mech)
10 pages, 10 figures, 83 references
Highly Enhanced robust room temperature ferromagnetism in CVD-grown nano-dimensional MoS2 flakes by modifying edges and defect engineering
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-28 20:00 EDT
Sharmistha Dey, Nahid Chaudhary, Ulrich Kentsch, Rajendra Singh, Pankaj Srivastava, Santanu Ghosh
The alterations in the magnetic properties and electronic structure of chemical vapor deposition (CVD) grown nano-dimensional molybdenum disulfide (MoS2) after low energy ion irradiation are thoroughly investigated. The formation of pure hexagonal 2-H phase has been identified by Raman spectroscopy and X-ray diffraction (XRD). The pristine samples are irradiated by Argon (Ar) ions with low energy at different fluences. A comprehensive analysis of Raman spectroscopy data manifests the formation of lattice defects like S-vacancies across the samples after irradiation. Triangular-flake formation in the pristine sample is confirmed by field emission scanning electron microscopy (FESEM) images. After increasing irradiation fluences the big flakes commenced to fragment into smaller ones enhancing the number of edge-terminated structures. The electron probe microanalyzer (EPMA) analysis verifies the absence of any magnetic impurity. Rutherford backscattering spectrometry (RBS) and X-ray photoelectron spectroscopy (XPS) study confirm the formation of S-vacancies after irradiation. The pristine sample exhibits diamagnetic behavior at room temperature. The saturation magnetization value increases with increasing the ion irradiation fluences, and the sample irradiated with 1e15 ions/cm2 demonstrates the highest magnetization value of 4.18 emu/g. The impact of edge-terminated structure and point defects like S-vacancies to induce room-temperature ferromagnetism (RTFM) is thoroughly examined.
Materials Science (cond-mat.mtrl-sci)
Magnetic Field Dependence of the Spin Susceptibility on Conventional s-wave Superconductor LaRu$4$P${12}$ Revealed by $^{31}$P-NMR and $^{139}$La-NMR
New Submission | Superconductivity (cond-mat.supr-con) | 2025-05-28 20:00 EDT
Riku Matsubayashi, Shiki Ogata, Taishi Ihara, Hiroyasu Matsudaira, Shunsaku Kitagawa, Kenji Ishida, Yusuke Nakai, Hitoshi Sugawara, Hideyuki Sato
The magnetic field dependence of the spin part of Knight shift, which is proportional to the superconducting-state spin susceptibility, was investigated at two nuclear sites, $ ^{31}$ P and $ ^{139}$ La in a conventional s-wave superconductor LaRu$ _4$ P$ _{12}$ . After the analyses, we confirmed that the superconducting-state spin susceptibility is proportional to magnetic field, and connects to the normal-state spin susceptibility smoothly. This is a textbook example, when the superconductivity is broken with the orbital pair-breaking effect.
Superconductivity (cond-mat.supr-con)
5 pages, 6 figures
J. Phys. Soc. Jpn. 94, 063706 (2025)
Reconfigurable Defect States in Non-Hermitian Topolectrical Chains with Gain and Loss
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-28 20:00 EDT
S. M. Rafi-Ul-Islam, Zhuo Bin Siu, Md Saddam Hossain Razo, Mansoor B.A. Jalil
We investigate the interplay between the non-Hermitian skin effect (NHSE), parity-time (PT) symmetry, and topological defect states in a finite non-Hermitian Su-Schrieffer-Heeger (SSH) chain. In the conventional NHSE regime, non-reciprocal hopping leads to an asymmetric localization of all eigenstates at one edge of the system, including the bulk and topological edge states. However, the introduction of staggered gain and loss restores the symmetric localization of topological edge states while preserving the bulk NHSE. We further examine the response of defect states in this system, demonstrating that their spatial localization is dynamically controlled by the combined effects of NHSE and PT symmetry. Specifically, we identify three distinct regimes in which the defect states localize at the defect site, shift to the system’s edges, or become completely delocalized. These findings extend beyond previous works that primarily explored the activation and suppression of defect states through gain-loss engineering. To validate our theoretical predictions, we propose an experimental realization using a topolectrical circuit, where non-Hermitian parameters are implemented via impedance converter-based non-reciprocal elements. Circuit simulations confirm the emergence and tunability of defect states through voltage and admittance measurements, providing a feasible platform for experimental studies of non-Hermitian defect engineering. Our results establish a route for designing reconfigurable non-Hermitian systems with controllable topological defect states, with potential applications in robust signal processing and sensing.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Other Condensed Matter (cond-mat.other)
13 pages, 6 figures
Spatial organisation of multiple species of active particles interacting with an interface
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-28 20:00 EDT
Love Grover, Rajeev Kapri, Abhishek Chaudhuri
We investigate the steady-state organisation of active particles residing on an interface. Particle activity induces interface deformations, while the local shape of the interface guides particle movement. We consider multiple species of particles which can locally pull on the interface or push it. This coupled system exhibits a wide variety of behaviours, including clustering, anti-clustering, diffusion, mixing, demixing, and localisation. Our findings suggest that one can control surface properties by strategically adding or removing specific particle types. Furthermore, by adjusting particle activity levels, we can selectively disperse particle types, enabling precise manipulation of surface movement and geometry.
Soft Condensed Matter (cond-mat.soft)
10 Pages, 10 figures, 2 tables
Phys. Rev. E 111, 045412, Published 11 April, 2025
Observation of charge density wave excitonic order parameter in topological insulator monolayer WTe2
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-28 20:00 EDT
Liam Watson, Joan Ripoll, Zhengjue Tong, Amit Kumar, Yande Que, Yang-Hao Chan, Hsin Lin, Shantanu Mukherjee, Manuela Garnica, Mark T. Edmonds, Michał Papaj, Amadeo L. Vazquez de Parga, Bent Weber, Iolanda Di Bernardo, Michael S. Fuhrer
Strong electron-hole interactions in a semimetal or narrow-gap semiconductor may drive a ground state of condensed excitons. Monolayer WTe2 has been proposed as a host material for such an exciton condensate, but the order parameter - the key signature of a macroscopic quantum-coherent condensate - has not been observed. Here we use Fourier-transform scanning tunnelling spectroscopy (FT-STS) to study quasi-particle interference (QPI) and periodic modulations of the local density of states (LDOS) in monolayer WTe2. In WTe2 on graphene, in which the carrier density can be varied via back-gating, FT-STS shows QPI features in the 2D bulk bands, confirming the interacting nature of the bandgap in neutral WTe2 and the semi-metallic nature of highly n- and p-doped WTe2. We observe additional non-dispersive spatial modulations in the LDOS imprinted on the topological edge mode of neutral WTe2 on metallic substrates (graphene and graphite), which we interpret as the interaction of the topological edge mode with the expected charge density wave order parameter of the excitonic condensate in WTe2 at low interaction strength due to screening by the metallic substrates.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
14 pages, 4 figures in the main text
Ferroelastic Altermagnetism
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-28 20:00 EDT
Rui Peng, Shibo Fang, Junwei Liu, Yee Sin Ang
Synergizing altermagnetism and other ferroic orders, such as ferroelectric switchable altermagnetism [Phys. Rev. Lett. 134, 106801 (2025) and ibid. 106802 (2025)], offers an effective route to achieve nonvolatile switching of altermagnetic spin splitting. In this work, by synergizing altermagnetism and ferroelasticity, we propose the concept of ferroelastic altermagnets in which the ferroelastic crystal reorientation can drive multistate nonvolatile switching of the altermagnetic spin splitting via altermagnetoelastic effect. Using monolayers RuF4 and CuF2 as material candidates, we demonstrate 2-state and 3-state altermagnetic spin splitting switching as driven by ferroelastic strain states. Transport calculation shows that multistate spin conductivities can be ferroelastically encoded in an ferroelastic altermagnet, thus suggesting the potential of ferroelastic altermagnetic as nonvolatile nanomechanical spin switches. The proposed concept of ferroelastic altermagnetism enriches the emerging landscape of multiferroic altermagnetism, paving a way towards altermagnetic-based straintronic device applications.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Applied Physics (physics.app-ph)
13 pages, 4 figures
Odd-parity magnetism by quantum geometry
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-28 20:00 EDT
We study the effects of quantum geometry on parity-violating magnetism that is classified as odd-parity multipole magnetism. By comparing the spin susceptibility and odd-parity multipole susceptibility in the multisublattice model, we find that the ferroic multipole fluctuation is induced by the quantum geometry of Bloch electrons over a wide range of parameters. Due to the Hubbard interaction, the quantum-geometric multipole fluctuations condense into the multipole order. We predict complex magnetic correlations, which are a signature of quantum-geometric multipole magnetism, and propose experimental verification.
Strongly Correlated Electrons (cond-mat.str-el)
Finding the right path: statistical mechanics of connected solutions in constraint satisfaction problems
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-05-28 20:00 EDT
We define and study a statistical mechanics ensemble that characterizes connected solutions in constraint satisfaction problems (CSPs). Built around a well-known local entropy bias, it allows us to better identify hardness transitions in problems where the energy landscape is dominated by isolated solutions. We apply this new device to the symmetric binary perceptron model (SBP), and study how its manifold of connected solutions behaves. We choose this particular problem because, while its typical solutions are isolated, it can be solved using local algorithms for a certain range of constraint density $ \alpha$ and threshold $ \kappa$ . With this new ensemble, we unveil the presence of a cluster composed of delocalized connected solutions. In particular, we demonstrate its stability until a critical threshold $ \kappa^{\rm no-mem}{\rm loc., stab.}$ (dependent on $ \alpha$ ). This transition appears as paths of solutions shatter, a phenomenon that more conventional statistical mechanics approaches fail to grasp. Finally, we compared our predictions to simulations. For this, we used a modified Monte-Carlo algorithm, designed specifically to target these delocalized solutions. We obtained, as predicted, that the algorithm finds solutions until $ \kappa\approx\kappa^{\rm no-mem}{\rm loc., stab.}$ .
Disordered Systems and Neural Networks (cond-mat.dis-nn), Statistical Mechanics (cond-mat.stat-mech)
Superstability of micrometer jets surrounded by a polymeric shell
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-28 20:00 EDT
A. Rubio, J. M. Montanero, M. Vakili, F. H. M. Koua, S. Bajt, H. N. Chapman, A. M. Gañán-Calvo
We have produced superstable compound liquid microjets with a three-dimensional printed coaxial flow-focusing injector. The aqueous jet core is surrounded by a shell, a few hundred nanometers in thickness, of a low-concentration aqueous solution of a low-molecular-weight polymer. Due to the stabilizing effect of the polymeric shell, the minimum liquid flow rate leading to stable flow-focusing is decreased by one order of magnitude, resulting in much thinner and longer jets. Possible applications of this technique for Serial Femtosecond X-ray Crystallography are discussed.
Soft Condensed Matter (cond-mat.soft), Fluid Dynamics (physics.flu-dyn)
Paper accepted for publication in Journal of Applied Crystallography
Determination of melting temperature of hexagonal ice using Lee-Yang phase transition theory
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-05-28 20:00 EDT
Ling Liu, Yihua Dong, Qijun Ye, Xin-Zheng Li
Lee-Yang phase transition theory is a milestone in statistical physics. Its applications in realistic systems, however, had been substantially hindered by availability of practical schemes to calculate the Lee-Yang zeros. In this manuscript, we extend the scheme we have designed earlier [Phys. Rev. E 109, 024118 (2024)] and report simulation results for the melting temperature (T) of ice Ih under ambient pressure. The enhanced sampling technique is shown to be crucial for accessing Lee-Yang zeros accurately. The real and imaginary parts of our Lee-Yang edges demonstrate linear scaling of sizes, which can lead to a melting T of 248.15 K for the TIP4P/2005 potential in the thermodynamic limit. This result is in close quantitative agreement with previous coexistence simulations, achieved with cheaper computational costs and without prior knowledge of the phase transition. With these, we demonstrate the applicability of Lee-Yang phase transition theory in realistic molecular systems, and provide a feasible scheme for high-throughput calculations in determining the phase transition temperature.
Statistical Mechanics (cond-mat.stat-mech)
10 pages, 8 figures
Effect of magnetic field and light on energy levels of (1+3+1) chirally twisted multilayer graphene system
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-28 20:00 EDT
Nadia Benlakhouy, Ahmed Jellal, Hocine Bahlouli, Pablo Díaz, David Laroze
We study the Hofstadter butterfly spectrum in (1+3+1) chirally twisted multilayer graphene (CTMLG) subject to perpendicular magnetic field and light with different polarizations. We focus on the interplay between twist angles and light-induced effects. In equilibrium, we examine symmetric ($ \theta_1 = \theta_2$ ) and asymmetric ($ \theta_1 \neq \theta_2$ ) configurations. Our results show that asymmetric configurations cause distinct effects in the electronic energy spectrum. However, the unique symmetry of the system ensures that the spectra remain identical when the twist angles are interchanged. This highlights the role of interlayer coupling in shaping the electronic structure of CTMLG. We then explored the effects of external periodic perturbations, such as circularly polarized light (CPL) and waveguide-generated linearly polarized light (WGL). CPL breaks chiral symmetry, creating a gap that distorts the Hofstadter spectrum. These distortions are more pronounced for asymmetric twist configurations. In contrast, WGL preserves chiral symmetry and has a tunable, non-monotonic effect on the bandwidth. This makes WGL a reliable tool for engineering electronic properties. These results demonstrate how (1+3+1)-CTMLG combines the effects of light-matter interactions with moiré physics. This allows accurate control of the electronic properties and fractal spectra by adjusting external fields and twist angles.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
13 pages, 8 figures. Version to appear in JSTAT 2025
Simulating generalised fluids via interacting wave packets evolution
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-05-28 20:00 EDT
Andrew Urilyon, Leonardo Biagetti, Jitendra Kethepalli, Jacopo De Nardis
One-dimensional integrable and quasi-integrable systems display, on macroscopic scales, a universal form of transport known as Generalized Hydrodynamics (GHD). In its standard Euler-scale formulation, GHD mirrors the equations of a two-dimensional compressible fluid but ignores fluctuations and becomes numerically unwieldy as soon as integrability-breaking perturbations are introduced. We show that GHD can be efficiently simulated as a gas of semiclassical wave packets - a natural generalisation of hard-rod particles - whose trajectories are efficiently mapped onto those of point particles. This representation (i) provides a transparent route to incorporate integrability-breaking terms, and (ii) automatically embeds the exact fluctuating-hydrodynamics extension of GHD. The resulting framework enables fast, large-scale simulations of quasi-integrable systems even in the presence of complicated integrability-breaking perturbations. It also manifest the pivotal role of two-point correlations in systems confined by external potentials: we demonstrate that situations where local one-point observables appear thermalised can nevertheless sustain long-lived, far-from-equilibrium long-range correlations for arbitrarily long times, signaling that, differently from what previously stated, true thermalisation is not reached at diffusive time-scales.
Statistical Mechanics (cond-mat.stat-mech), Strongly Correlated Electrons (cond-mat.str-el)
15 pages, 6 figures
The non-equilibrium thermodynamics of active suspensions
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-28 20:00 EDT
Active suspensions composed of self-propelled colloidal particles are considered. Their propulsion of is generated by chemical reactions occurring by heterogeneous catalysis and diffusiophoresis coupling the concentration gradients of reacting molecular species to the fluid velocity. By this mechanism, chemical free energy is transduced into mechanical motion. The non-equilibrium thermodynamics of such active suspensions is developed by explicitly taking into account the internal degrees of freedom of active particles, which are the Eulerian angles specifying their orientation. Accordingly, the distribution function of colloidal particles is defined in the six-dimensional configuration space of their position and their orientation, which fully characterises polar, nematic, and higher orientational orders in the active system. The local Gibbs and Euler thermodynamic relations are expressed in terms of the colloidal distribution function, the dynamics of which is ruled by a six-dimensional local conservation equation. All the processes contributing to the entropy production rate are derived from the local conservation and kinetic equations for colloids, molecular species, mass, linear momentum, and energy, identifying their thermodynamic forces, also called affinities, and their dissipative current densities. The non-equilibrium constitutive relations are obtained using the Curie symmetry principle and the Onsager-Casimir reciprocal relations based on microreversibility. In this way, all the mechanochemical coupling coefficients are completely determined for isothermal, incompressible, dilute suspensions composed of spherical Janus particles on the basis of the interfacial properties between the fluid solution and the solid particles and chemohydrodynamics. The complete expression of the entropy production rate is established for such active systems.
Soft Condensed Matter (cond-mat.soft), Chemical Physics (physics.chem-ph)
Nonreciprocal and long-range three-body interactions in Bose-Einstein condensates induced by optical feedback
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-05-28 20:00 EDT
Yi-Qing Zhang, Liang-Jun He, Han Pu, Zheng-Wei Zhou, Yong-Chang Zhang
We propose generating long-range and nonreciprocal three-body interactions in quantum gases via optical feedback. By placing a quasi-two-dimensional Bose-Einstein condensate (BEC) in front of two reflecting mirrors and illuminating it with dichromatic laser beams, these driving optical fields traverse the BEC twice, thereby inducing a feedback effect on the atoms. We demonstrate that this optical feedback gives rise to an effective three-body atom-atom interaction with remarkable long-range and nonreciprocal properties. Due to its long-range nature, this three-body interaction can cause unique spatial symmetry-breaking behaviors in the BEC, resulting in various stable stationary states as well as unexpected diffusive collapse. Notably, a distinct ring state emerges through a purely self-organizing process. Furthermore, by analyzing the real-time dynamics of the BEC, we show that the nonreciprocal nature of this interaction can lead to intriguing self-acceleration of the condensate, seemingly violating Newton’s law of motion. Additionally, our scheme offers a highly controllable setting, where pairwise two-body interactions can be tuned to vanish. This flexibility provides a promising route for exploring exotic physics associated with multi-body interactions.
Quantum Gases (cond-mat.quant-gas)
12 pages, 7 figures
Polaron formation as the vertex function problem: From Dyck’s paths to self-energy Feynman diagrams
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-28 20:00 EDT
Tomislav Miškić, Juraj Krsnik, Andrey S. Mishchenko, Osor S. Barišić
We present a novel iterative method for generating all self-energy Feynman diagrams of any given order for the single polaron problem. This approach offers an effective tool for circumventing the sign problem that often arises in approximation-free numerical summations of Feynman diagrams. Each iterative step begins by rigorously listing all noncrossing diagrams using the graphical Dyck path representation of Stieltjes-Rogers polynomials, which exactly encode the Feynman diagram series. In the second phase, the Ward-Takahashi identity is used to uniquely identify the complete subset of vertex function contributions from the self-energy diagrams obtained in the previous iterative step. Finally, the noncrossing diagrams and vertex function contributions are combined to construct the full set of Feynman diagrams at a given order of the diagrammatic expansion, determining the number of diagrams of various types. This approach establishes a systematic procedure for generating the total sum of diagrams in a given order, enabling significant sign cancellation and making it broadly suitable for numerical summation techniques involving Feynman diagrams.
Strongly Correlated Electrons (cond-mat.str-el), High Energy Physics - Phenomenology (hep-ph)
22 pages, 3 figures, 2 tables
Pseudomagnetotransport in Strained Graphene
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-28 20:00 EDT
Alina Mreńca-Kolasińska, Christophe De Beule, Jia-Tong Shi, Aitor Garcia-Ruiz, Denis Kochan, Klaus Richter, Ming-Hao Liu
In graphene, long-wavelength deformations that result in elastic shear strain couple to the low-energy Dirac electrons as pseudogauge fields. Using a scalable tight-binding model, we consider analogs to magnetotransport in mesoscopic strained graphene devices with nearly uniform pseudomagnetic fields. In particular, we consider transverse pseudomagnetic focusing in a bent graphene ribbon and show that a focused valley-polarized current can be generated with characteristic conductance oscillations. Importantly, our scaling method allows for quantum transport calculations with realistic device geometries, and leaves the Dirac physics and pseudogauge fields invariant as long as the atomic displacements vary slowly with respect to the scaled lattice. Our results show that pseudomagnetotransport is a promising new route for graphene straintronics, and our scaling method provides a new framework for the modeling, design, and interpretation of straintronics experiments and applications.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
7 pages + 9 pages supplementary file, 12 figures
In-situ nanoscale transport measurements on monoatomic metal films by low-temperature scanning tunneling potentiometry
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-28 20:00 EDT
Masayuki Hamada, Masahiro Haze, Junya Okazaki, Yukio Hasegawa
Investigation of transport properties is fundamental for characterizing electronic properties and phase transitions. However, most of the transport measurements on conductive layers have been performed at macroscopic scales, and thus the development of microscopic methods to measure transport is important. Scanning tunneling potentiometry (STP) is a powerful tool for investigating surface conductivity at nano-scale spatial resolutions. However, it is still challenging to conduct STP studies at low temperatures and most of the low-temperature studies were performed on samples that were prepared ex-situ. In this study, we developed a low-temperature STP and demonstrated its performance on monoatomic metal films formed on Si(111) substrates that were prepared in-situ. Stable operation at low temperatures enables us to extract the electrochemical potential originating from the surface transport by canceling out the potential due to thermal differences and artifacts arising from the nonlinearity of the density of states (DOS). We also formulated the nonlinear-DOS artifact and confirmed it by comparing with the nonlinearity obtained by scanning tunneling spectroscopy.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
18 pages, 7 figures
Hydrostatic pressure studies on non-superconducting UTe2
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-28 20:00 EDT
M. O. Ajeesh, Joe D. Thompson, Eric D. Bauer, Filip Ronning, Sean M. Thomas, Priscila F. S. Rosa
We report the temperature-pressure phase diagram of a UTe$ _2$ single crystal that does not undergo a bulk superconducting transition but shows filamentary superconductivity with a critical transition temperature of 1 K at ambient pressure. Electrical-resistivity measurements reveal that the evolution of the filamentary superconducting state under pressure resembles the behavior observed in previous reports on bulk superconducting samples. AC calorimetry, however, does not show evidence for either bulk superconductivity or magnetism for pressures up to 1.6 GPa. Our results highlight the role of inhomogeneity in chemical-vapor-transport-grown UTe$ _2$ samples and serve as a cautionary tale when probing electrical resistivity alone.
Strongly Correlated Electrons (cond-mat.str-el), Superconductivity (cond-mat.supr-con)
7 pages, 2 figures
J. Phys. Soc. Jpn. 93, 055001 (2024)
Ordered buckling structures in a twisted crimped tube
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-28 20:00 EDT
Pan Dong, Nathan C. Keim, Joseph D. Paulsen
When a ribbon or tube is twisted far enough it forms buckles and wrinkles. Its new geometry can be strikingly ordered, or hopelessly disordered. Here we study this process in a tube with hybrid boundary conditions: one end a cylinder, and the other end crimped flat like a ribbon, so that the sample resembles a toothpaste tube. The resulting irregular structures and mechanical responses can be dramatically different from those of a ribbon. However, when we form two creases in the tube prior to twisting, we obtain an ordered structure composed of repeating triangular facets oriented at varying angles, and a more elastic torque response, reminiscent of the creased helicoid structure of a twisted ribbon. We measure how the torque and structural evolution depend on parameters such as material thickness and the twist angle. When only part of the tube is pre-creased, the ordered structures are confined to this segment. Surprisingly, in some tubes made from thicker sheets, an ordered structure forms without pre-creasing. This study provides insights into controlling the buckling of thin shells, offering a potential pathway for designing ordered structures in soft materials.
Soft Condensed Matter (cond-mat.soft)
7 pages, 7 figures
Modeling of Water Evaporation in Hydrogels from Aspect of Mechanical Analytics
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-28 20:00 EDT
Zehua Yu, Yongshun Ren, Kang Liu
Water evaporation is critically important for hydrogels in open-air applications, but theoretically modeling is difficult due to the complicated intermolecular interactions and sustained deformation. In this work, we construct a simplified model to describe the state of water inside the hydrogel by only considering mechanical stretching. We employ “negative pressure” to bridge the stretching force in water and elastic force generated by the polymer network. Combined with a constitutive equation of elasticity for hydrogels and classic diffusion equation, this model gives a universal solution to calculate the saturated vapor pressure, dynamic evaporation rates and real-time deformation of different hydrogels. The calculated results agree well with experiments results both in steady state and dynamic process for commonly used poly 2-hydroxyethyl methacrylate and polyacrylamide hydrogels with diverse components. In addition, the model predicts that, hydrogels with high modulus shows stronger ability to retain water in open environment.
Soft Condensed Matter (cond-mat.soft)
Anomalous supercurrents in the presence of particle losses
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-05-28 20:00 EDT
We show that supercurrent properties in a superfluid or superconducting junction are significantly modified due to single-particle losses present in a conduction channel. In the presence of a spin-independent particle loss, we find regimes where the Josephson current $ I_N(\phi)$ takes zero at a position in between $ \phi= 0$ and $ \phi=\pi$ , and the direction of the supercurrent is reversed. Although the region is narrow, we also find a regime in which the critical current is enhanced by dissipation. Such anomalous behaviors in the Josephson current are attributed to a subtle interplay between the contribution that is present regardless of dissipation and the unconventional one that is absent without dissipation. In the presence of a spin-selective particle loss, it is shown that a dissipation-induced spin supercurrent and its reversal occur. The proposed system is analyzed by means of the Keldysh field theory approach based on the Gorini-Kossakowski-Sudershan-Lindblad master equation and may be realized in ultracold atomic gases and solid-state systems.
Quantum Gases (cond-mat.quant-gas), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Superconductivity (cond-mat.supr-con)
10 pages, 9 figures
Ultrafast atomic dimerization of Peierls distortion in semimetal molybdenum ditelluride
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-28 20:00 EDT
Zhong Wang, Chunlong Hu, Changchang Gong, Fuyong Hua, Qian You, Wenxi Liang
Semimetal molybdenum ditelluride (1T’-MoTe$ _2$ ) possess diverse phase transitions enriching its application prospects. The structural response during these transitions is crucial to understanding the underlying mechanisms, but the desired details of pathway and time span are still insufficient. Here, we investigate the lattice evolution in few-layer 1T’-MoTe$ _2$ after photoexcitation, using ultrafast electron diffraction and density functional theory (DFT) calculations. The observed complex lattice responses with unintuitively evolving Bragg peak intensity and interplanar spacing, are best interpreted as the combination of shear displacement and Mo-Mo bond shortening in a few picoseconds, and a metastable structure in nanoseconds, basing on the analyses of structure factor and pair distribution function. The DFT calculations reveal that, the photodoped electrons induced population change of the antibonding states close to Fermi level, lead to the shear displacement and the dimerization of Mo pairs. Our findings present new insights for elucidating the picture of Peierls distortion in 1T’-MoTe$ _2$ .
Materials Science (cond-mat.mtrl-sci)
12 pages, 6 figures
Stability of binary Bose mixtures with attractive intercomponent interactions
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-05-28 20:00 EDT
Abdulla Rakhimov, Sanathon Tukhtasinova, Vyacheslav I. Yukalov
In 2015 Dmitry Petrov theoretically predicted that, in binary mixture of bosons a quantum liquid droplet may arise due to the competition between attractive intercomponent and repulsive intracomponent forces. Although this prediction has been confirmed experimentally, the model by itself suffers from a serious conceptual problem: The low - lying excitation spectrum manifests a purely imaginary phonon velocity, $ c_d^2 < 0$ . In present work we develop self consistent theory of two component Bose system with attractive inter species interaction, which accurately takes into account pair correlations in terms of anomalous and mixed densities. We have shown that this procedure is able to resolve the problem of $ c_d^2 < 0$ . Limiting ourselves with a symmetric Bose mixture at zero temperature, we have found a region of stability in which a droplet may survive.
Quantum Gases (cond-mat.quant-gas)
27 pages, 15 figures
Optically detected magnetic resonance of wafer-scale hexagonal boron nitride thin films
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-28 20:00 EDT
Sam C. Scholten, Jakub Iwański, Kaijian Xing, Johannes Binder, Aleksandra K. Dąbrowska, Hark H. Tan, Tin S. Cheng, Jonathan Bradford, Christopher J. Mellor, Peter H. Beton, Sergei V. Novikov, Jan Mischke, Sergej Pasko, Emre Yengel, Alexander Henning, Simonas Krotkus, Andrzej Wysmołek, Jean-Philippe Tetienne
Hexagonal boron nitride (hBN) has recently been shown to host native defects exhibiting optically detected magnetic resonance (ODMR) with applications in nanoscale magnetic sensing and imaging. To advance these applications, deposition methods to create wafer-scale hBN films with controlled thicknesses are desirable, but a systematic study of the ODMR properties of the resultant films is lacking. Here we perform ODMR measurements of thin films (3-2000nm thick) grown via three different methods: metal-organic chemical vapour deposition (MOCVD), chemical vapour deposition (CVD), and molecular beam epitaxy (MBE). We find that they all exhibit an ODMR response, including the thinnest 3nm film, albeit with different characteristics. The best volume-normalised magnetic sensitivity obtained is 30uT/sqrt(Hz um^3). We study the effect of growth temperature on a series of MOCVD samples grown under otherwise fixed conditions and find 800-900C to be an optimum range for magnetic sensitivity, with a significant improvement (up to two orders of magnitude) from post-growth annealing. This work provides a useful baseline for the magnetic sensitivity of hBN thin films deposited via standard methods and informs the feasibility of future sensing applications.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Factor of 1000 suppression of the depolarization rate in ultracold thulium collisions
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-05-28 20:00 EDT
I.A. Pyrkh, A.E. Rudnev, D.A. Kumpilov, I.S. Cojocaru, V.A. Khlebnikov, P.A. Aksentsev, A.M. Ibrahimov, K.O. Frolov, S.A. Kuzmin, A.K. Zykova, D.A. Pershin, V.V. Tsyganok, A.V. Akimov
Lanthanides are nowadays extensively used to investigate the properties of strongly correlated matter. Nevertheless, exploiting the Zeeman manifold of a lanthanide atom ground state is challenging due to the unavoidable presence of depolarization collisions. Here we demonstrate that in the case of the thulium atom, it is possible to suppress this depolarization by a factor of 1000 with a carefully tuned magnetic field thus opening the way for the efficient use of the Zeeman manifold in quantum simulations.
Quantum Gases (cond-mat.quant-gas), Atomic Physics (physics.atom-ph)
Atomistic and experimental study of microstructural evolution in nanocrystalline iron subjected to irradiation
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-28 20:00 EDT
Ivan Tolkachev, Daniel R. Mason, Max Boleininger, Pui-Wai Ma, Daniel Long, Eamonn T. Connolly, Stephen P. Thompson, Kenichiro Mizohata, Felix Hofmann
Nanocrystalline materials have been proposed for use in future fusion reactors due to their high grain boundary density that may act as a sink for irradiation-induced defects. We use molecular dynamics to model collision cascades in nanocrystalline iron and compare the damage evolution to that observed in initially perfect, single crystalline iron. The nanocrystalline material is generated either by Voronoi tessellation or severe plastic shearing. Upon irradiation, the grains in nanocrystalline simulations coarsen, with all ultimately becoming single crystalline above 2 dpa. Above a damage dose of 1 dpa, nanocrystalline cells show a lower dislocation density and lower lattice swelling than their initially pristine counterparts. Experimental X-ray diffraction data is collected on nanocrystalline iron samples subjected to self-ion irradiation. Line profile analysis data agrees with the trends observed in the atomistic simulations, revealing the presence of an irradiation induced annealing process, with a clear reduction in micro-strain with increasing dose. We attempt to determine why some grains in our atomistic simulations grow, while others shrink, by creating a Toy Model that simulates volume exchange between grains based on different hypothesised exchange mechanisms. This suggests that irradiation-induced grain growth is consistent with random growth.
Materials Science (cond-mat.mtrl-sci)
Disentangling the Roles of Dissolved Oxygen, Common Salts, and pH on the Spontaneous Hydrogen Peroxide Production in Water: No O2, No H2O2
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-28 20:00 EDT
Muzzamil Ahmad Eatoo, Himanshu Mishra
Despite the mounting evidence proving that the air-water interface or the microdroplet geometry has nothing to do with the spontaneous formation of hydrogen peroxide (H2O2), the myth persists. Three recent studies by George and co-workers give credence to the myth by showing connections between the spontaneous formation of hydroxyl (HO) radicals and hydrogen peroxide (H2O2) in sprayed microdroplets with the solution pH, dissolved salts, nebulizing gas, and the gaseous environment. They report that among halides (chloride, bromide, and iodide), bromide dominates the H2O2 formation because of its ability to donate electrons. Also, they conclude that the H2O2 production at the air-water interface scales with waters alkalinity. In response, we apply a broad set of techniques, spanning NMR, potentiodynamic polarization, electron microscopy, and hydrogen peroxide assay kit (HPAK) fluorometry, to reexamine these claims. Our experiments reveal that regardless of the halide present in water, the air-water interface or the microdroplet geometry does not drive the H2O2 formation. It is the reduction of O2 at the solid-water interface that produces H2O2, i.e., in the absence of O2, no H2O2 is formed regardless of the halide ions. We explain the relative dependence of H2O2 concentrations on the halides based on their propensity to drive pitting corrosion (Chloride > Bromide > Iodide). As the pits appear in the passivating layer, exposing the metal, H2O2 is consumed in further oxidation. Next, we disprove the claim of alkalinity-driven H2O2 formation by demonstrating that aluminum and titanium surfaces produce more H2O2 in acidic and alkaline conditions, respectively. Taken together, these findings refute the conclusions of George and co-workers and others regarding spontaneous H2O2 generation at the air-water interface. The following mnemonic captures our conclusion: no O2, no H2O2.
Soft Condensed Matter (cond-mat.soft)
Hydrodynamics in generalized electronic two-band systems
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-28 20:00 EDT
E. Di Salvo, P. Cosme, L. Fritz
In this paper, we derive the Euler and Navier-Stokes equations for electronic two-band systems in arbitrary dimension and with generic power-law dispersion relations. We focus on the hydrodynamic transport regime, where such systems offer a unique tunability between a Fermi-liquid type regime at high doping and the inherent two-band physics of the low-density system close to the Dirac-type band-touching point. For a generic dispersion, the absence of Euclidean or Lorentzian invariance leads to novel types of hydrodynamic equations. We characterize these novel hydrodynamic regimes through dimensionless numbers, such as the Prandtl and Lorenz numbers, or the ratio between shear viscosity and entropy density. In all cases, we provide a derivation of the physics of the long-wavelength plasmonic modes.
Strongly Correlated Electrons (cond-mat.str-el)
16 pages, 7 figures
Spectroscopy and Ground-State Transfer of Ultracold Bosonic $^{39}$K$^{133}$Cs Molecules
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-05-28 20:00 EDT
Krzysztof P. Zamarski, Charly Beulenkamp, Yi Zeng, Manuele Landini, Hanns-Christoph Nägerl
We report on the creation of ultracold samples of $ ^{39}$ K$ ^{133}$ Cs molecules in their rovibrational ground state. By investigating potentially suitable excited states using one- and two-photon spectroscopy, we have identified a pathway to the ground state via an exceptionally narrow intermediate state. Using Stimulated Raman Adiabatic Passage (STIRAP), we create trapped samples of up to 3500 molecules at temperatures of 1 $ \mu$ K with one-way efficiencies of 71%. The lifetime of these samples is limited by a universal-rate two-body loss process, which could shed new light on similar loss mechanisms in other molecular species. Our results are a step towards establishing an alternative platform for the study of bosonic and fermionic quantum matter with strong dipolar interactions.
Quantum Gases (cond-mat.quant-gas), Atomic Physics (physics.atom-ph)
Functional renormalization group approach to phonon modified criticality: anomalous dimension of strain and non-analytic corrections to Hooke’s law
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-05-28 20:00 EDT
Max O. Hansen, Julia von Rothkirch, Peter Kopietz
We study the interplay between critical isotropic elasticity and classical Ising criticality using a functional renormalization group (FRG) approach which is implemented such that the volume is fixed during the entire renormalization group flow. For dimensions slightly smaller than four we use a simple truncation of the FRG flow equations to recover the fixed points of the constrained Ising model: the Gaussian fixed point G, the Ising fixed point I, the renormalized Ising fixed point R, and the spherical fixed point S. We show that the fixed points R and S are both characterized by a finite anomalous dimension $ y_{\ast}<0$ of strain fluctuations, implying that the energy dispersion of longitudinal acoustic phonons exhibits a non-analytic momentum dependence proportional to $ k^{1-y_{\ast}/2}$ for small momentum $ k$ . We also derive and solve flow equations for the free energy at constant strain and compute stress-strain relations in the vicinity of the fixed points. As a result, we reaffirm that Ising criticality, controlled by the fixed point I, is preempted by a bulk instability. Beyond that, we find that the stress-strain relation at R and S remains linear to leading order (Hooke’s law), as long as the interaction between strain and Ising fluctuations is sufficiently weak. However, the finite anomalous dimension of strain fluctuations $ y_{\ast}$ gives rise to non-analytic corrections to Hooke’s law.
Statistical Mechanics (cond-mat.stat-mech), Other Condensed Matter (cond-mat.other)
21 pages, 13 figures
Large strain contribution to the laser-driven magnetization response of magnetostrictive TbFe$_{2}$
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-28 20:00 EDT
C. Walz, F.-C. Weber, S.-P. Zeuschner, K. Dumesnil, A. von Reppert, M. Bargheer
We investigate strain-induced contributions to the transient polar magneto-optical Kerr effect response in laser-excited terfenol. The tr-MOKE signals obtained from TbFe$ _{2}$ films with and without glass capping exhibit distinct signatures associated with transient strain. We experimentally observe the arrival of strain pulses via the reflectivity change. The tr-MOKE response measured without changing the pump-probe geometry is delayed by several picoseconds. This suggests a genuine magnetization response as opposed to instantaneous changes of optical constants as the origin of the signal. We model the propagation of longitudinal acoustic picosecond strain pulses and incorporate the inverse magnetostriction effect via a magnetoelastic term in the effective field of the Landau-Lifshitz-Gilbert equation with large damping. This reproduces not only the delay of the pulsed response, but also unveils the dominant contribution of quasi-static strain to the magnetization dynamics due to the thermal expansion in the optically probed near-surface region. Our experiments exemplify that purely longitudinal strain along the out-of-plane direction of the thin film enables efficient magnetoelastic coupling via the shear strain components arising in the oblique crystallographic frame of reference.
Materials Science (cond-mat.mtrl-sci)
12 pages, 8 figures, submitted to: Applied Physics Letters
Charge Carrier Mobilities in gamma-Graphynes: A computational approach
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-28 20:00 EDT
Elif Unsal (1), Alessandro Pecchia (2), Alexander Croy (3), Gianaurelio Cuniberti (1, 4) ((1) Institute for Materials Science and Nanotechnology, (2) CNR-ISMN, (3) Institute of Physical Chemistry, (4) Dresden Center for Computational Materials Science (DCMS))
Graphynes, a class of two-dimensional carbon allotropes, exhibit exceptional electronic properties, similar to graphene, but with intrinsic band gaps, making them promising for semiconducting applications. The incorporation of acetylene linkages allows for systematic modulation of their properties. However, the theoretical characterization of graphynes remains computationally demanding, particularly for electron-phonon coupling (EPC) analyses. Here, we employ the density functional tight binding method within the DFTBephy framework, providing an efficient and accurate approach for computing EPC and transport properties. We investigate the structural, mechanical, electronic, and transport properties of graphynes, comparing transport calculations using the constant relaxation-time approximation and the self-energy relaxation-time approximation (SERTA) alongside analytical models based on parabolic- and Kane-band approximations. For graphyne, the SERTA relaxation time is 0.63 (1.69) ps for holes (electrons). In graphdiyne, the relaxation time is 0.04 (0.14) ps for holes (electrons). While the hole mobilities in graphyne are on the order of 10$ ^3$ cm$ ^2/$ Vs, the electron mobilities reach up to 10$ ^4$ cm$ ^2/$ Vs. In graphdiyne, the mobility values for both types of charge carriers are on the order of 10$ ^2$ cm$ ^2/$ Vs. The phonon-limited mobilities at room temperature in graphyne fall between those of graphene and MoS$ _2$ , while in graphdiyne, they are comparable to those of MoS$ _2$ .
Materials Science (cond-mat.mtrl-sci)
From Polyhedra to Crystals: A Graph-Theoretic Framework for Crystal Structure Generation
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-28 20:00 EDT
Tomoyasu Yokoyama, Kazuhide Ichikawa, Hisashi Naito
Crystal structures can be viewed as assemblies of space-filling polyhedra, which play a critical role in determining material properties such as ionic conductivity and dielectric constant. However, most conventional crystal structure prediction methods rely on random structure generation and do not explicitly incorporate polyhedral tiling, limiting their efficiency and interpretability. In this highlight, we introduced a novel crystal structure generation method based on discrete geometric analysis of polyhedral information. The geometry and topology of space-filling polyhedra are encoded as a dual periodic graph, and the corresponding crystal structure is obtained via the standard realization of this graph. We demonstrate the effectiveness of our approach by reconstructing face-centered cubic (FCC), hexagonal close-packed (HCP), and body-centered cubic (BCC) structures from their dual periodic graphs. This method offers a new pathway for systematically generating crystal structures based on target polyhedra, potentially accelerating the discovery of novel materials for applications in electronics, energy storage, and beyond.
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
11 pages, 10 figures
Strain controlled g- to d-wave transition in altermagnetic CrSb
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-28 20:00 EDT
Bennet Karetta, Xanthe H. Verbeek, Rodrigo Jaeschke-Ubiergo, Libor Šmejkal, Jairo Sinova
The possibility of a strain-induced transformation from $ g$ -wave to $ d$ -wave altermagnetism was recently recently proposed for MnTe using a $ k\cdot p$ perturbative model. In this work, we demonstrate such a transition in CrSb for a wider array of strains, using a combination of a minimal model and first-principles calculations. Starting from a symmetry perspective, we analyze the spin elastoconductivity tensor, and determine the strain types which allow for a change in the altermagnetic symmetry. We obtain three strain directions, which allow for a $ d$ -wave type splitting, and one in which a net magnetic moment emerges. Using first-principles calculations in the absence of spin-orbit coupling (SOC), we confirm these symmetry predictions. Furthermore, these results do not alter qualitatively in the presence of SOC. Finally, we reveal that the resulting spin currents give rise to a spin-splitter effect of up to 5% under realistic strains of 1%, confirming strain as a powerful tool for tuning altermagnetic properties.
Materials Science (cond-mat.mtrl-sci), Other Condensed Matter (cond-mat.other), Computational Physics (physics.comp-ph)
Graphene/hBN heterostructure based Valley transistor: Dynamic Control of valley current in synchronized nonzero voltages, within the time-dependent regime
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-28 20:00 EDT
A. Belayadi, C. I. Osuala, I. Assi, A. Naif, J. P. F. LeBlanc, A. Abbout
Graphene/hexagonal boron nitride (hBN) heterostructures represent a promising class of metal-insulator-semiconductor systems widely explored for multifunctional digital device applications. In this work, we demonstrate that graphene, when influenced by carrier-dependent trapping in the hBN spacer triggered by a localized potential from Kelvin probe force microscopy (KPFM), can exhibit valley transistor behavior under specific conditions. We employ a tight-binding model that self-consistently incorporates a Gaussian-shaped potential to represent the effect of the tip gate. Crucially, we show that the heterostructure functions as a field-effect transistor (FET), with its operation governed by the bias gate (shifting the Fermi level) and the tip-induced potential (breaking electron-hole symmetry via selective trapping of electron or hole quasiparticles). Our results reveal that, under specific lattice geometry, pulse frequency, and gate voltage conditions, the device exhibits valley transistor functionality. The valley current (e.g., I_K1=-K or I_K2=+K) can be selectively controlled by synchronizing the frequencies and polarities of the tip and bias gate voltages. Notably, when both gates are driven with the same polarity, the graphene channel outputs a periodically modulated, pure valley-polarized current. This enables switching between distinct ON/OFF valley current states even at finite bias. Remarkably, when the I_K1=-K current is ON (forward current), the I_K2=+K current is OFF. Reversing the gate polarity inverts this behavior: I_K1=-K turns OFF, while I_K2=+K turns ON (reverse current). These findings pave the way toward low-voltage valley transistors in metal-insulator-semiconductor architectures, offering new avenues for valleytronics and advanced gating technologies.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Low-energy, ultrafast spin reorientation at competing hybrid interfaces with tunable operating temperature
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-28 20:00 EDT
Servet Ozdemir, Matthew Rogers, Jaka Strohsack, Hari Babu Vasili, Manuel Valvidares, Thahabh Haddadi, Parvathy Harikumar, David ORegan, Gilberto Teobaldi, Timothy Moorsom, Mannan Ali, Gavin Burnell, B J Hickey, Tomaz Mertelj, Oscar Cespedes
Information can be stored in magnetic materials by encoding with the direction of the magnetic moment of elements. A figure of merit for these systems is the energy needed to change the information rewrite the storage by changing the magnetic moment. Organic molecules offer a playground to manipulate spin order, with metallo molecular interfaces being a promising direction for sustainable devices. Here, we demonstrate a spin reorientation transition in molecular interfaces of high magnetisation 3d ferromagnetic films due to a competition between a perpendicular magnetic anisotropy (PMA) induced by a heavy metal that dominates at high temperatures, and an in-plane anisotropy generated by molecular coupling at low temperatures. The transition can be tuned around room temperature by varying the ferromagnet thickness (1.4 to 1.9 nm) or the choice of molecular overlayer, with the organic molecules being C60, hydrogen and metal (Cu, Co) phthalocyanines. Near the transition temperature, the magnetisation easy axis can be switched with a small energy input, either electrically with a current density of 10^5 A per cm2, or optically by a fs laser pulse of fluence as low as 0.12 mJ per cm2, suggesting heat assisted technology applications. Magnetic dichroism measurements point toward a phase transition at the organic interface being responsible for the spin reorientation transition.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
Current-induced spin and orbital polarization in the ferroelectric Rashba semiconductor GeTe
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-28 20:00 EDT
Sergio Leiva-Montecinos, Libor Vojáček, Jing Li, Mairbek Chshiev, Laurent Vila, Ingrid Mertig, Annika Johansson
The Edelstein effect is a promising mechanism for generating spin and orbital polarization from charge currents in systems without inversion symmetry. In ferroelectric materials, such as Germanium Telluride (GeTe), the combination of bulk Rashba splitting and voltage-controlled ferroelectric polarization provides a pathway for electrical control of the sign of the charge-spin conversion. In this work, we investigate current-induced spin and orbital magnetization in bulk GeTe using Wannier-based tight-binding models derived from \textit{ab initio} calculations and semiclassical Boltzmann theory. Employing the modern theory of orbital magnetization, we demonstrate that the orbital Edelstein effect entirely dominates its spin counterpart. This difference is visualized through the spin and orbital textures at the Fermi surfaces, where the orbital moment surpasses the spin moment by one order of magnitude. Moreover, the orbital Edelstein effect remains largely unaffected in the absence of spin-orbit coupling, highlighting its distinct physical origin compared to the spin Edelstein effect.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Marie Skłodowska-Curie Actions, H2020-MSCA-ITN-2020; Project acronym SPEAR; Grant Agreement No. 955671
A Thermally Modulated SINIS Trasconductance Amplifier
New Submission | Superconductivity (cond-mat.supr-con) | 2025-05-28 20:00 EDT
Giacomo Trupiano, Giorgio De Simoni, Francesco Giazotto
We introduce a superconducting transconductance amplifier based on the thermal modulation of a SINIS (Superconductor-Insulator-Normal metal-Insulator-Superconductor) configuration. The device is composed of a normal metal island interfaced with two superconducting leads through tunnel barriers, establishing a voltage-biased symmetric SINIS setup. An additional NIS junction connects the island to a third superconducting lead, which serves as input. When the input voltage surpasses the superconducting gap, the resultant injection of quasiparticles increases the electronic temperature of the island, thereby modulating the SINIS current. We perform numerical analyzes of the device performance, influenced by input voltage, frequency, and bath temperature. At bath temperatures below 250 mK, the device shows a transconductance exceeding 4 mS and a current gain exceeding 45 dB. Both gain and transconductance maintain their levels up to 1 MHz, but decrease at higher frequencies, with a -3 dB cutoff around 10 MHz, and an average power dissipation of approximately 5 nW. Our simulations reveal a fully voltage-controlled, three-terminal superconducting amplifier characterized by high transconductance and gain, achieved through thermally mediated signal transduction. This architectural design presents a promising avenue for cryogenic amplification with reduced power dissipation and compatibility with current superconducting electronic systems.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
7 pages, 3 figures
Efficient production of sodium Bose-Einstein condensates in a hybrid trap
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-05-28 20:00 EDT
Yanda Geng, Shouvik Mukherjee, Swarnav Banik, Monica Gutierrez Galan, Madison J. Anderson, Hector Sosa-Martinez, Stephen P. Eckel, Ian B. Spielman, Gretchen K. Campbell
We describe an apparatus that efficiently produces $ ^{23}$ Na Bose-Einstein condensates (BECs) in a hybrid trap that combines a quadrupole magnetic field with a far-detuned optical dipole trap. Using a Bayesian optimization framework, we systematically optimize all BEC production parameters in modest sized batches of highly correlated parameters. Furthermore, we introduce a Lagrange multiplier-based technique to optimize the duration of different evaporation stages constrained to have a fixed total duration; this enables the progressive creation of increasingly rapid experimental sequences that still generate high quality BECs. Taken together, our techniques constitute a general approach for refining and accelerating sequence-based experimental protocols.
Quantum Gases (cond-mat.quant-gas), Instrumentation and Detectors (physics.ins-det)
10 pages, 6 figures
Interpretable machine learned predictions of adsorption energies at the metal–oxide interface
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-28 20:00 EDT
Marius Juul Nielsen, Luuk H. E. Kempen, Julie de Neergaard Ravn, Raffaele Cheula, Mie Andersen
The conversion of $ \mathrm{CO_2}$ to value-added compounds is an important part of the effort to store and reuse atmospheric $ \mathrm{CO_2}$ emissions. Here we focus on $ \mathrm{CO_2}$ hydrogenation over so-called inverse catalysts: transition metal oxide clusters supported on metal surfaces. The conventional approach for computational screening of such candidate catalyst materials involves a reliance on density functional theory (DFT) to obtain accurate adsorption energies at a significant computational cost. Here we present a machine learning (ML)-accelerated workflow for obtaining adsorption energies at the metal–oxide interface. We enumerate possible binding sites at the clusters and use DFT to sample a subset of these with diverse local adsorbate environments. The data set is used to explore interpretable and black-box ML models with the aim to reveal the electronic and structural factors controlling adsorption at metal–oxide interfaces. Furthermore, the explored ML models can be used for low-cost prediction of adsorption energies on structures outside of the original training data set. The workflow presented here, along with the insights into trends in adsorption energies at metal–oxide interfaces, will be useful for identifying active sites, predicting parameters required for microkinetic modeling of reactions on complex catalyst materials, and accelerating data-driven catalyst design.
Materials Science (cond-mat.mtrl-sci)
12 pages, 6 figures, 3 tables + supplementary material (15 pages, 13 figures, 6 tables) – submitted to JCP
Degradation and SEI Evolution in Alloy Anodes Revealed by Correlative Liquid-Cell Electrochemistry and Cryogenic Microscopy
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-28 20:00 EDT
Neil Mulcahy, Syeda Ramin Jannat, Geri Topore, Lukas Worch, James O. Douglas, Baptiste Gault, Mary P. Ryan, Michele Shelly Conroy
Understanding solid liquid interfaces at high spatial and chemical resolution is crucial for advancing electrochemical energy storage technologies, yet this remains a persistent challenge due to the lack of characterisation techniques that can capture dynamic processes and preserve fragile interfacial chemistries. In lithium ion batteries, interfacial phenomena such as lithium alloying, solid electrolyte interphase formation, and electrode degradation play a decisive role in capacity retention and failure mechanisms but are difficult to observe in their native state due to high mobility, reactivity, and low atomic number of lithium. Here, we use a recently introduced correlative operando characterisation approach that integrates electrochemical liquid cell transmission electron microscopy with cryogenic atom probe tomography to resolve the evolution of a platinum alloy anode at the solid liquid interface during electrochemical cycling. This correlative, cryo enabled workflow reveals spatially heterogeneous SEI formation, the presence of lithium carbonate rich inner SEI layers, and the retention of elemental lithium within the platinum electrode, most likely trapped along grain boundaries. Additionally, we observe the formation of mossy lithium structures and irreversible lithium loss through dead lithium accumulation. Our results provide direct mechanistic insight into lithium alloying and degradation pathways in alloy based anodes and establish a generalised platform for probing dynamic electrochemical interfaces with complementary structural and chemical sensitivity. The methodology is broadly applicable to next generation electrode materials and electrochemical devices where interfacial dynamics dictate performance and stability.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
Superconducting Acoustogalvanic Effect in Twisted Transition Metal Dichalcogenides
New Submission | Superconductivity (cond-mat.supr-con) | 2025-05-28 20:00 EDT
Tsugumi Matsumoto, Ryotaro Sano, Youichi Yanase, Akito Daido
The recently discovered twisted bilayer superconductors have suffered from a lack of reliable methods for identifying their nontrivial pairing symmetries and quantum geometry. In this study, we propose nonlinear responses driven by surface acoustic waves as a novel probe to access exotic Bogoliubov quasiparticles in such superconductors. Our approach is particularly suitable for addressing the superconducting gap structure as the gap energies in these systems typically lie within the frequency range of surface acoustic waves, and thus paves the way toward the experimental identification of exotic superconducting states especially in low-$ T_c$ superconductors.
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
11 pages, 5 figures
Tuning Ultra-Narrow Direct Bandgap in alpha-Sn Nanocrystals: A CMOS-Compatible Approach for THz Applications
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-28 20:00 EDT
Tiziano Bertoli, Elena Stellino, Francesco Minati, Camilla Belloni, Giovanni Tomassucci, Emanuele Bosco, Silvano Battisti, Leonardo Puppulin, Demetrio Logoteta, Alessandro Nucara, Luisa Barba, Gaetano Campi, Naurang Lal Saini, Fabrizio Palma, Michele Back, Pietro Riello, Fernanda Irrera
alpha-Sn has recently been attracting significant interest due to its unique electronic properties. However, this allotrope of Sn is stable only below 13 °C and alternative options to the conventional stabilization by epitaxial growth on InSb are still a challenge. In this work, nanoparticles with inner alpha-Sn nanocrystals were synthesized on a Silicon substrate via a CMOS-compatible process through microwave irradiation. The nanoparticle morphology was characterized by Scanning Electron Microscopy and Atomic Force Microscopy, demonstrating the ability to control the nanoparticle size by a dewetting process combined with a coalescence process induced by the microwaves. Grazing Incidence X-Ray Diffraction analyses confirmed the stabilization of the alpha-Sn phase within a SnO2 shell, while X-Ray Photoemission Spectroscopy measurements revealed the presence of a bandgap. Infrared transmission spectroscopy combined with a Tauc-plot extrapolation led to an estimate of the gap in the range from 64 to 137 meV range. Furthermore, the possibility to tune the bandgap by controlling the nanoparticle size, possibly leveraging weak quantum confinement effects, was demonstrated, unveiling the potential of alpha-Sn nanoparticles on Si for the development of CMOS-compatible THz devices.
Materials Science (cond-mat.mtrl-sci)
34 pages, 5 figures
Full stochastic dynamics of a tracer in a dense single-file system
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-05-28 20:00 EDT
Alexis Poncet, Aurélien Grabsch, Olivier Bénichou
Tracer diffusion in single-file systems, where particles are restricted to move on a line without passing each other, has been a fertile ground to investigate anomalous diffusion and strong memory effects. While the long-time behavior of such a tracer has been well studied, with a known subdiffusive dynamics and a Gaussian description for the rescaled position, the finer details of multi-time correlations remain poorly understood. This work focuses on the limit where almost all sites of a Symmetric Exclusion Process (SEP), a paradigmatic lattice model, are occupied. It extends beyond Gaussian descriptions and single-time statistics to address the multi-time correlation functions of the tracer in the SEP. In this dense limit, we present a general relation between all $ n$ -time correlations of the non-Markovian tracer position process and the conditional probabilities of a single Markovian random walker. Using this relation, we derive explicit expressions for the four-time correlations and further explore important extensions: multiple tracers, non-equilibrium situations, and finite observation times. Our results underscore significant memory effects, strong temporal correlations, and the influence of initial conditions on long-time dynamics.
Statistical Mechanics (cond-mat.stat-mech)
Pair binding and Hund’s rule breaking in high-symmetry fullerenes
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-28 20:00 EDT
Highly-symmetric molecules often exhibit degenerate tight-binding states at the Fermi edge. This typically results in a magnetic ground state if small interactions are introduced in accordance with Hund’s rule. In some cases, Hund’s rule may be broken, which signals pair binding and goes hand-in-hand with an attractive pair-binding energy. We investigate pair binding and Hund’s rule breaking for the Hubbard model on high-symmetry fullerenes C$ _{20}$ , C$ _{28}$ , C$ _{40}$ , and C$ _{60}$ by using massive, large-scale density-matrix renormalization group calculations. We exploit the SU(2) spin symmetry, the U(1) charge symmetry, and optionally the Z(N) spatial rotation symmetry of the problem. For C$ {20}$ , our results agree well with available exact-diagonalization data, but our approach is numerically much cheaper. We find a Mott transition at $ U_c\sim2.2t$ , which is much smaller than the previously reported value of $ U_c\sim4.1t$ that was extrapolated from a few datapoints. We compute the pair-binding energy for arbitrary values of $ U$ and observe that it remains overall repulsive. For larger fullerenes, we are not able to evaluate the pair binding energy with sufficient precision, but we can still investigate Hund’s rule breaking. For C$ {28}$ , we find that Hund’s rule is fulfilled with a magnetic spin-2 ground state that transitions to a spin-1 state at $ U{c,1}\sim5.4t$ before the eventual Mott transition to a spin singlet takes place at $ U{c,2}\sim 11.6t$ . For C$ _{40}$ , Hund’s rule is broken in the singlet ground state, but is restored if the system is doped with one electron. Hund’s rule is also broken for C$ _{60}$ , and the doping with two or three electrons results in a minimum-spin state. Our results support an electronic mechanism of superconductivity for C$ _{60}$ lattices. We speculate that the high geometric frustration of small fullerenes is detrimental to pair binding.
Strongly Correlated Electrons (cond-mat.str-el)
Chiral Anomaly Induced Transverse Planar Transport Phenomena in Three Dimensional Spin-Orbit Coupled Metals
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-28 20:00 EDT
Rishi G. Gopalakrishnan, Binayyak B. Roy, Gargee Sharma, Sumanta Tewari
We investigate linear and nonlinear transverse planar transport phenomena (viz. linear and nonlinear Hall and Nernst coefficients) induced by chiral anomaly in three-dimensional spin-orbit coupled metallic systems. Unlike Weyl semimetals, these systems do not possess multiple Weyl nodes located at isolated points in the momentum space but instead host a pair of Fermi surfaces characterized by opposite Berry curvature fluxes enclosing the same band-degeneracy point. Using semiclassical Boltzmann transport formalism within the relaxation time approximation, we derive first- and second-order transverse planar transport coefficients induced by electrical and thermal gradients in the presence of an in-plane magnetic field. Our analysis reveals distinctive angular dependencies of the transport coefficients, along with characteristic scaling behavior with the magnetic field strength. Furthermore, we demonstrate that the anomaly-induced transport coefficients exhibit an exponential temperature dependence. This unconventional behavior leads to the violations of the Mott relation at comparatively low temperatures, highlighting unique thermoelectric signatures that can be probed experimentally in 3D spin-orbit coupled metallic systems.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
13 pages, 8 figures
Tunable intertwining via collective excitations
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-05-28 20:00 EDT
The intertwining of multiple order parameters is a widespread phenomenon in equilibrium condensed matter systems, yet its exploration is often hindered by the complexity of real materials. Here, we present a controlled study of intertwined orders in a minimal driven-dissipative quantum-engineered platform. We consider a Bose-Einstein condensate at the intersection of two optical cavities, realizing two competing copies of a $ \mathbb{Z}_2$ symmetry-breaking superradiant phase transition characterized by density wave orders. We show that collective excitations emerging at the order-to-order transition can be harnessed via periodic driving to stabilize a variety of dynamical phases, including intertwined orders. Our drive exploits dynamical symmetry reduction to generate a tunable mass gap in the excitation spectrum, offering a versatile mechanism for engineering intertwined dynamical orders in quantum-optical platforms.
Quantum Gases (cond-mat.quant-gas)
9 pages, 3 figures